Commit Graph

1848 Commits

Author SHA1 Message Date
Li Zefan
3aaba20f26 tracing: Fix a race in function profile
While we are reading trace_stat/functionX and someone just
disabled function_profile at that time, we can trigger this:

	divide error: 0000 [#1] PREEMPT SMP
	...
	EIP is at function_stat_show+0x90/0x230
	...

This fix just takes the ftrace_profile_lock and checks if
rec->counter is 0. If it's 0, we know the profile buffer
has been reset.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: stable@kernel.org
LKML-Reference: <4C723644.4040708@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-31 16:46:23 -04:00
Frederic Weisbecker
98ee74a75c Merge branch 'perf/urgent' into perf/core
Conflicts:
	tools/perf/util/callchain.h

Merge reason:
	Fix a non-trivial conflict with latest fixes
2010-08-27 02:30:07 +02:00
Anton Blanchard
151772dbfa tracing/trace_stack: Fix stack trace on ppc64
save_stack_trace() stores the instruction pointer, not the
function descriptor. On ppc64 the trace stack code currently
dereferences the instruction pointer and shows 8 bytes of
instructions in our backtraces:

 # cat /sys/kernel/debug/tracing/stack_trace
        Depth    Size   Location    (26 entries)
        -----    ----   --------
  0)     5424     112   0x6000000048000004
  1)     5312     160   0x60000000ebad01b0
  2)     5152     160   0x2c23000041c20030
  3)     4992     240   0x600000007c781b79
  4)     4752     160   0xe84100284800000c
  5)     4592     192   0x600000002fa30000
  6)     4400     256   0x7f1800347b7407e0
  7)     4144     208   0xe89f0108f87f0070
  8)     3936     272   0xe84100282fa30000

Since we aren't dealing with function descriptors, use %pS
instead of %pF to fix it:

 # cat /sys/kernel/debug/tracing/stack_trace
        Depth    Size   Location    (26 entries)
        -----    ----   --------
  0)     5424     112   ftrace_call+0x4/0x8
  1)     5312     160   .current_io_context+0x28/0x74
  2)     5152     160   .get_io_context+0x48/0xa0
  3)     4992     240   .cfq_set_request+0x94/0x4c4
  4)     4752     160   .elv_set_request+0x60/0x84
  5)     4592     192   .get_request+0x2d4/0x468
  6)     4400     256   .get_request_wait+0x7c/0x258
  7)     4144     208   .__make_request+0x49c/0x610
  8)     3936     272   .generic_make_request+0x390/0x434

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: rostedt@goodmis.org
Cc: fweisbec@gmail.com
LKML-Reference: <20100825013238.GE28360@kryten>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-25 13:08:48 +02:00
Ingo Molnar
c8710ad389 Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core 2010-08-19 12:48:09 +02:00
Namhyung Kim
6016ee13db perf, tracing: add missing __percpu markups
ftrace_event_call->perf_events, perf_trace_buf,
fgraph_data->cpu_data and some local variables are percpu pointers
missing __percpu markups. Add them.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <1281498479-28551-1-git-send-email-namhyung@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-08-19 01:33:05 +02:00
Frederic Weisbecker
7ae07ea3a4 perf: Humanize the number of contexts
Instead of hardcoding the number of contexts for the recursions
barriers, define a cpp constant to make the code more
self-explanatory.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
2010-08-19 01:32:53 +02:00
Li Zefan
86397dc3cc tracing: Clean up seqfile code for format file
Remove the nasty hack that marks a pointer's LSB to distinguish common
fields from event fields. Replace it with a more sane approach.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4C6A23C2.9020606@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-18 11:09:14 -04:00
Steven Rostedt
d244b6bd41 Merge branch 'tip/perf/urgent-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into trace/tip/perf/urgent-4
Conflicts:
	kernel/trace/trace_events.c

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-16 11:17:30 -04:00
Marcin Slusarz
1aa54bca6e tracing: Sanitize value returned from write(trace_marker, "...", len)
When userspace code writes non-new-line-terminated string to trace_marker
file, write handler appends new-line and returns number of bytes written
to trace buffer, so
write(fd, "abc", 3) will return 4

That's unexpected and unfortunately it confuses glibc's fprintf function.

Example:
int main() {
  fprintf(stderr, "abc");
  return 0;
}

$ gcc test.c -o test
$ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer
$ ./test 2>/sys/kernel/debug/tracing/trace_marker

results in infinite loop:
write(fd, "abc", 3) = 4
write(fd, "", 1) = 0
write(fd, "", 1) = 0
write(fd, "", 1) = 0
write(fd, "", 1) = 0
write(fd, "", 1) = 0
write(fd, "", 1) = 0
write(fd, "", 1) = 0
(...)

...and kernel trace buffer full of empty markers.

Fix it by sanitizing write return value.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
LKML-Reference: <20100727231801.GB2826@joi.lan>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-13 15:23:16 -04:00
Steven Rostedt
2a37a3df57 tracing/events: Convert format output to seq_file
Two new events were added that broke the current format output.

Both from the SCSI system: scsi_dispatch_cmd_done and scsi_dispatch_cmd_timeout

The reason is that their print_fmt exceeded a page size. Since the output
of the format used simple_read_from_buffer and trace_seq, it was limited
to a page size in output.

This patch converts the printing of the format of an event into seq_file,
which allows greater than a page size to be shown.

I diffed all event formats comparing the output with and without this
patch. All matched except for the above two, which showed just:

  FORMAT TOO BIG

without this patch, but now properly displays the output with this patch.

v2: Remove updating *pos in seq start function.
   [ Thanks to Li Zefan for pointing that out ]

Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Cc: James Bottomley <James.Bottomley@suse.de>
Cc: Tomohiro Kusumi <kusumi.tomohiro@jp.fujitsu.com>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-12 16:59:29 -04:00
Adrian Hunter
8d57a98ccd block: add secure discard
Secure discard is the same as discard except that all copies of the
discarded sectors (perhaps created by garbage collection) must also be
erased.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Gardiner <bengardiner@nanometrics.ca>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-12 08:43:30 -07:00
Jiri Kosina
6396fc3b3f Merge branch 'master' into for-next
Conflicts:
	fs/exofs/inode.c
2010-08-11 09:36:51 +02:00
Linus Torvalds
2f9e825d3e Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits)
  block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n
  xen-blkfront: fix missing out label
  blkdev: fix blkdev_issue_zeroout return value
  block: update request stacking methods to support discards
  block: fix missing export of blk_types.h
  writeback: fix bad _bh spinlock nesting
  drbd: revert "delay probes", feature is being re-implemented differently
  drbd: Initialize all members of sync_conf to their defaults [Bugz 315]
  drbd: Disable delay probes for the upcomming release
  writeback: cleanup bdi_register
  writeback: add new tracepoints
  writeback: remove unnecessary init_timer call
  writeback: optimize periodic bdi thread wakeups
  writeback: prevent unnecessary bdi threads wakeups
  writeback: move bdi threads exiting logic to the forker thread
  writeback: restructure bdi forker loop a little
  writeback: move last_active to bdi
  writeback: do not remove bdi from bdi_list
  writeback: simplify bdi code a little
  writeback: do not lose wake-ups in bdi threads
  ...

Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and
drivers/scsi/scsi_error.c as per Jens.
2010-08-10 15:22:42 -07:00
Jiri Kosina
fb8231a8b1 Merge branch 'master' into for-next
Conflicts:
	arch/arm/mach-omap1/board-nokia770.c
2010-08-10 13:22:08 +02:00
Paul Bolle
426d31071a fix printk typo 'faild'
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-08-09 11:25:17 +02:00
Linus Torvalds
78417334b5 Merge branch 'bkl/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing
* 'bkl/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
  do_coredump: Do not take BKL
  init: Remove the BKL from startup code
2010-08-07 17:06:54 -07:00
Linus Torvalds
3b7433b8a8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (55 commits)
  workqueue: mark init_workqueues() as early_initcall()
  workqueue: explain for_each_*cwq_cpu() iterators
  fscache: fix build on !CONFIG_SYSCTL
  slow-work: kill it
  gfs2: use workqueue instead of slow-work
  drm: use workqueue instead of slow-work
  cifs: use workqueue instead of slow-work
  fscache: drop references to slow-work
  fscache: convert operation to use workqueue instead of slow-work
  fscache: convert object to use workqueue instead of slow-work
  workqueue: fix how cpu number is stored in work->data
  workqueue: fix mayday_mask handling on UP
  workqueue: fix build problem on !CONFIG_SMP
  workqueue: fix locking in retry path of maybe_create_worker()
  async: use workqueue for worker pool
  workqueue: remove WQ_SINGLE_CPU and use WQ_UNBOUND instead
  workqueue: implement unbound workqueue
  workqueue: prepare for WQ_UNBOUND implementation
  libata: take advantage of cmwq and remove concurrency limitations
  workqueue: fix worker management invocation without pending works
  ...

Fixed up conflicts in fs/cifs/* as per Tejun. Other trivial conflicts in
include/linux/workqueue.h, kernel/trace/Kconfig and kernel/workqueue.c
2010-08-07 12:42:58 -07:00
Arnd Bergmann
62c2a7d969 block: push BKL into blktrace ioctls
The blktrace driver currently needs the BKL, but
we should not need to take that in the block layer,
so just push it down into the driver itself.

It is quite likely that the BKL is not actually
required in blktrace code and could be removed
in a follow-on patch.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:26:08 +02:00
Christoph Hellwig
7b6d91daee block: unify flags for struct bio and struct request
Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver.  There were two flags in the bio that were
missing in the requests:  BIO_RW_UNPLUG and BIO_RW_AHEAD.  Also I've
renamed two request flags that had a superflous RW in them.

Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:20:39 +02:00
Christoph Hellwig
33659ebbae block: remove wrappers for request type/flags
Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests.  This allows much easier grepping for different request
types instead of unwinding through macros.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:17:56 +02:00
Linus Torvalds
b62ad9ab18 Merge branch 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  um: Fix read_persistent_clock fallout
  kgdb: Do not access xtime directly
  powerpc: Clean up obsolete code relating to decrementer and timebase
  powerpc: Rework VDSO gettimeofday to prevent time going backwards
  clocksource: Add __clocksource_updatefreq_hz/khz methods
  x86: Convert common clocksources to use clocksource_register_hz/khz
  timekeeping: Make xtime and wall_to_monotonic static
  hrtimer: Cleanup direct access to wall_to_monotonic
  um: Convert to use read_persistent_clock
  timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset
  powerpc: Cleanup xtime usage
  powerpc: Simplify update_vsyscall
  time: Kill off CONFIG_GENERIC_TIME
  time: Implement timespec_add
  x86: Fix vtime/file timestamp inconsistencies

Trivial conflicts in Documentation/feature-removal-schedule.txt

Much less trivial conflicts in arch/powerpc/kernel/time.c resolved as
per Thomas' earlier merge commit 47916be4e2 ("Merge branch
'powerpc.cherry-picks' into timers/clocksource")
2010-08-06 13:18:29 -07:00
Huang Ying
18fab912d4 tracing: Fix ring_buffer_read_page reading out of page boundary
With the configuration: CONFIG_DEBUG_PAGEALLOC=y and Shaohua's patch:

[PATCH]x86: make spurious_fault check correct pte bit

Function call graph trace with the following will trigger a page fault.

# cd /sys/kernel/debug/tracing/
# echo function_graph > current_tracer
# cat per_cpu/cpu1/trace_pipe_raw > /dev/null

BUG: unable to handle kernel paging request at ffff880006e99000
IP: [<ffffffff81085572>] rb_event_length+0x1/0x3f
PGD 1b19063 PUD 1b1d063 PMD 3f067 PTE 6e99160
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
last sysfs file: /sys/devices/virtual/net/lo/operstate
CPU 1
Modules linked in:

Pid: 1982, comm: cat Not tainted 2.6.35-rc6-aes+ #300 /Bochs
RIP: 0010:[<ffffffff81085572>]  [<ffffffff81085572>] rb_event_length+0x1/0x3f
RSP: 0018:ffff880006475e38  EFLAGS: 00010006
RAX: 0000000000000ff0 RBX: ffff88000786c630 RCX: 000000000000001d
RDX: ffff880006e98000 RSI: 0000000000000ff0 RDI: ffff880006e99000
RBP: ffff880006475eb8 R08: 000000145d7008bd R09: 0000000000000000
R10: 0000000000008000 R11: ffffffff815d9336 R12: ffff880006d08000
R13: ffff880006e605d8 R14: 0000000000000000 R15: 0000000000000018
FS:  00007f2b83e456f0(0000) GS:ffff880002100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff880006e99000 CR3: 00000000064a8000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process cat (pid: 1982, threadinfo ffff880006474000, task ffff880006e40770)
Stack:
 ffff880006475eb8 ffffffff8108730f 0000000000000ff0 000000145d7008bd
<0> ffff880006e98010 ffff880006d08010 0000000000000296 ffff88000786c640
<0> ffffffff81002956 0000000000000000 ffff8800071f4680 ffff8800071f4680
Call Trace:
 [<ffffffff8108730f>] ? ring_buffer_read_page+0x15a/0x24a
 [<ffffffff81002956>] ? return_to_handler+0x15/0x2f
 [<ffffffff8108a575>] tracing_buffers_read+0xb9/0x164
 [<ffffffff810debfe>] vfs_read+0xaf/0x150
 [<ffffffff81002941>] return_to_handler+0x0/0x2f
 [<ffffffff810248b0>] __bad_area_nosemaphore+0x17e/0x1a1
 [<ffffffff81002941>] return_to_handler+0x0/0x2f
 [<ffffffff810248e6>] bad_area_nosemaphore+0x13/0x15
Code: 80 25 b2 16 b3 00 fe c9 c3 55 48 89 e5 f0 80 0d a4 16 b3 00 02 c9 c3 55 31 c0 48 89 e5 48 83 3d 94 16 b3 00 01 c9 0f 94 c0 c3 55 <8a> 0f 48 89 e5 83 e1 1f b8 08 00 00 00 0f b6 d1 83 fa 1e 74 27
RIP  [<ffffffff81085572>] rb_event_length+0x1/0x3f
 RSP <ffff880006475e38>
CR2: ffff880006e99000
---[ end trace a6877bb92ccb36bb ]---

The root cause is that ring_buffer_read_page() may read out of page
boundary, because the boundary checking is done after reading. This is
fixed via doing boundary checking before reading.

Reported-by: Shaohua Li <shaohua.li@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: Huang Ying <ying.huang@intel.com>
LKML-Reference: <1280297641.2771.307.camel@yhuang-dev>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-06 14:34:45 -04:00
Linus Torvalds
c4efd6b569 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (27 commits)
  sched: Use correct macro to display sched_child_runs_first in /proc/sched_debug
  sched: No need for bootmem special cases
  sched: Revert nohz_ratelimit() for now
  sched: Reduce update_group_power() calls
  sched: Update rq->clock for nohz balanced cpus
  sched: Fix spelling of sibling
  sched, cpuset: Drop __cpuexit from cpu hotplug callbacks
  sched: Fix the racy usage of thread_group_cputimer() in fastpath_timer_check()
  sched: run_posix_cpu_timers: Don't check ->exit_state, use lock_task_sighand()
  sched: thread_group_cputime: Simplify, document the "alive" check
  sched: Remove the obsolete exit_state/signal hacks
  sched: task_tick_rt: Remove the obsolete ->signal != NULL check
  sched: __sched_setscheduler: Read the RLIMIT_RTPRIO value lockless
  sched: Fix comments to make them DocBook happy
  sched: Fix fix_small_capacity
  powerpc: Exclude arch_sd_sibiling_asym_packing() on UP
  powerpc: Enable asymmetric SMT scheduling on POWER7
  sched: Add asymmetric group packing option for sibling domain
  sched: Fix capacity calculations for SMT4
  sched: Change nohz idle load balancing logic to push model
  ...
2010-08-06 09:39:22 -07:00
Linus Torvalds
4aed2fd8e3 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (162 commits)
  tracing/kprobes: unregister_trace_probe needs to be called under mutex
  perf: expose event__process function
  perf events: Fix mmap offset determination
  perf, powerpc: fsl_emb: Restore setting perf_sample_data.period
  perf, powerpc: Convert the FSL driver to use local64_t
  perf tools: Don't keep unreferenced maps when unmaps are detected
  perf session: Invalidate last_match when removing threads from rb_tree
  perf session: Free the ref_reloc_sym memory at the right place
  x86,mmiotrace: Add support for tracing STOS instruction
  perf, sched migration: Librarize task states and event headers helpers
  perf, sched migration: Librarize the GUI class
  perf, sched migration: Make the GUI class client agnostic
  perf, sched migration: Make it vertically scrollable
  perf, sched migration: Parameterize cpu height and spacing
  perf, sched migration: Fix key bindings
  perf, sched migration: Ignore unhandled task states
  perf, sched migration: Handle ignored migrate out events
  perf: New migration tool overview
  tracing: Drop cpparg() macro
  perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call
  ...

Fix up trivial conflicts in Makefile and drivers/cpufreq/cpufreq.c
2010-08-06 09:30:52 -07:00
Shaohua Li
575570f027 tracing: Fix an unallocated memory access in function_graph
With CONFIG_DEBUG_PAGEALLOC, I observed an unallocated memory access in
function_graph trace. It appears we find a small size entry in ring buffer,
but we access it as a big size entry. The access overflows the page size
and touches an unallocated page.

Cc: <stable@kernel.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
LKML-Reference: <1280217994.32400.76.camel@sli10-desk.sh.intel.com>
[ Added a comment to explain the problem - SDR ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-06 12:19:15 -04:00
Jason Wessel
19063c776f ftrace,kdb: Allow dumping a specific cpu's buffer with ftdump
In systems with more than one processor it is desirable to look at the
per cpu trace buffers.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
2010-08-05 09:22:23 -05:00
Jason Wessel
955b61e597 ftrace,kdb: Extend kdb to be able to dump the ftrace buffer
Add in a helper function to allow the kdb shell to dump the ftrace
buffer.

Modify trace.c to expose the capability to iterate over the ftrace
buffer in a read only capacity.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
2010-08-05 09:22:23 -05:00
Srikar Dronamraju
9da79ab83e tracing/kprobes: unregister_trace_probe needs to be called under mutex
Comment in unregister_trace_probe() says probe_lock will be held when it
gets called. However there is a case where it might called without the
probe_lock being held. Also since we are traversing the probe_list and
deleting an element from the probe_list, probe_lock should be held.

This was first pointed in uprobes traceevent review by Frederic
Weisbecker here.  (http://lkml.org/lkml/2010/5/12/106)

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100630084548.GA10325@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-08-04 12:41:23 -03:00
Frederic Weisbecker
669336e4cf perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call
We use synchronize_sched() to ensure a tracepoint won't be called
while/after we release the perf buffers it references.

But the tracepoint API has its own API for that:
tracepoint_synchronize_unregister(). Use it instead as it's
self-explanatory and eases maintainance.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
2010-08-02 01:30:56 +02:00
John Stultz
592913ecb8 time: Kill off CONFIG_GENERIC_TIME
Now that all arches have been converted over to use generic time via
clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME
config option and simplify the generic code.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-27 12:40:54 +02:00
Ingo Molnar
3a01736e70 Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core 2010-07-23 09:10:29 +02:00
Dan Carpenter
24a461d537 trace: strlen() return doesn't account for the NULL
We need to add one to the strlen() return because of the NULL
character.  The type->name here generally comes from the kernel and I
don't think any of them come close to being MAX_TRACER_SIZE (100)
characters long so this is basically a cleanup.

Signed-off-by: Dan Carpenter <error27@gmail.com>
LKML-Reference: <20100710100644.GV19184@bicker>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-07-22 14:56:41 -04:00
Ingo Molnar
dca45ad8af Merge branch 'linus' into sched/core
Merge reason: Move from the -rc3 to the almost-rc6 base.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-21 21:45:08 +02:00
KOSAKI Motohiro
ef710e100c tracing: Shrink max latency ringbuffer if unnecessary
Documentation/trace/ftrace.txt says

  buffer_size_kb:

        This sets or displays the number of kilobytes each CPU
        buffer can hold. The tracer buffers are the same size
        for each CPU. The displayed number is the size of the
        CPU buffer and not total size of all buffers. The
        trace buffers are allocated in pages (blocks of memory
        that the kernel uses for allocation, usually 4 KB in size).
        If the last page allocated has room for more bytes
        than requested, the rest of the page will be used,
        making the actual allocation bigger than requested.
        ( Note, the size may not be a multiple of the page size
          due to buffer management overhead. )

        This can only be updated when the current_tracer
        is set to "nop".

But it's incorrect. currently total memory consumption is
'buffer_size_kb x CPUs x 2'.

Why two times difference is there? because ftrace implicitly allocate
the buffer for max latency too.

That makes sad result when admin want to use large buffer. (If admin
want full logging and makes detail analysis). example, If admin
have 24 CPUs machine and write 200MB to buffer_size_kb, the system
consume ~10GB memory (200MB x 24 x 2). umm.. 5GB memory waste is
usually unacceptable.

Fortunatelly, almost all users don't use max latency feature.
The max latency buffer can be disabled easily.

This patch shrink buffer size of the max latency buffer if
unnecessary.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
LKML-Reference: <20100701104554.DA2D.A69D9226@jp.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-07-21 10:20:17 -04:00
Lai Jiangshan
bc289ae98b tracing: Reduce latency and remove percpu trace_seq
__print_flags() and __print_symbolic() use percpu trace_seq:

1) Its memory is allocated at compile time, it wastes memory if we don't use tracing.
2) It is percpu data and it wastes more memory for multi-cpus system.
3) It disables preemption when it executes its core routine
   "trace_seq_printf(s, "%s: ", #call);" and introduces latency.

So we move this trace_seq to struct trace_iterator.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4C078350.7090106@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-07-20 22:05:34 -04:00
Richard Kennedy
985023dee6 trace: Reorder struct ring_buffer_per_cpu to remove padding on 64bit
Reorder structure to remove 8 bytes of padding on 64 bit builds.
This shrinks the size to 128 bytes so allowing allocation from a smaller
slab & needed one fewer cache lines.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
LKML-Reference: <1269516456.2054.8.camel@localhost>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-07-20 21:58:44 -04:00
Li Zefan
e870e9a124 tracing: Allow to disable cmdline recording
We found that even enabling a single trace event that will rarely be
triggered can add big overhead to context switch.

(lmbench context switch test)
 -------------------------------------------------
 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
 ctxsw  ctxsw  ctxsw ctxsw  ctxsw   ctxsw   ctxsw
------ ------ ------ ------ ------ ------- -------
  2.19   2.3   2.21   2.56   2.13     2.54    2.07
  2.39   2.51  2.35   2.75   2.27     2.81    2.24

The overhead is 6% ~ 11%.

It's because when a trace event is enabled 3 tracepoints (sched_switch,
sched_wakeup, sched_wakeup_new) will be activated to map pid to cmdname.

We'd like to avoid this overhead, so add a trace option '(no)record-cmd'
to allow to disable cmdline recording.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4C2D57F4.2050204@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-07-20 21:52:33 -04:00
Arnd Bergmann
b444786f1a tracing: Use generic_file_llseek for debugfs
The default for llseek will change to no_llseek,
so the tracing debugfs files need to add explicit
.llseek assignments. Since we're dealing with regular
files from a VFS perspective, use generic_file_llseek.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Kacur <jkacur@redhat.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <1278538820-1392-10-git-send-email-arnd@arndb.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-07-20 14:31:24 +02:00
Frederic Weisbecker
eb7beb5c09 tracing: Remove special traces
Special traces type was only used by sysprof. Lets remove it now
that sysprof ftrace plugin has been dropped.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Soeren Sandmann <sandmann@daimi.au.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
2010-07-20 14:31:07 +02:00
Frederic Weisbecker
f376bf5ffb tracing: Remove sysprof ftrace plugin
The sysprof ftrace plugin doesn't seem to be seriously used
somewhere. There is a branch in the sysprof tree that makes
an interface to it, but the real sysprof tool uses either its
own module or perf events.

Drop the sysprof ftrace plugin then, as it's mostly useless.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Soeren Sandmann <sandmann@daimi.au.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
2010-07-20 14:29:46 +02:00
Frederic Weisbecker
5d550467b9 tracing: Remove ksym tracer
The ksym (breakpoint) ftrace plugin has been superseded by perf
tools that are much more poweful to use the cpu breakpoints.
This tracer doesn't bring more feature. It has been deprecated
for a while now, lets remove it.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-07-15 23:59:33 +02:00
Arnd Bergmann
5e3d20a68f init: Remove the BKL from startup code
I have shown by code review that no driver takes
the BKL at init time any more, so whatever the
init code was locking against is no longer there
and it is now safe to remove the BKL there.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Steven Rostedt <rostedt@goodmis>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-07-09 15:40:32 +02:00
Masami Hiramatsu
e09c8614b3 tracing/kprobes: Support "string" type
Support string type tracing and printing in kprobe-tracer.

This allows user to trace string data in kernel including __user data. Note
that sometimes __user data may not be accessed if it is paged-out (sorry, but
kprobes operation should be done in atomic, we can not wait for page-in).

Commiter note: Fixed up conflicts with b7e2ece.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100519195724.2885.18788.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-07-05 15:54:45 -03:00
Tejun Heo
6416669975 workqueue: temporarily remove workqueue tracing
Strip tracing code from workqueue and remove workqueue tracing.  This
is temporary measure till concurrency managed workqueue is complete.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
2010-06-29 10:07:11 +02:00
Steven Rostedt
a1d0ce8213 tracing: Use class->reg() for all registering of events
Because kprobes and syscalls need special processing to register
events, the class->reg() method was created to handle the differences.

But instead of creating a default ->reg for perf and ftrace events,
the code was scattered with:

	if (class->reg)
		class->reg();
	else
		default_reg();

This is messy and can also lead to bugs.

This patch cleans up this code and creates a default reg() entry for
the events allowing for the code to directly call the class->reg()
without the condition.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-28 21:13:14 -04:00
Chase Douglas
d62f85d1e2 tracing/function-graph: Use correct string size for snprintf
The nsecs_str string is a local variable defined as:

char nsecs_str[5];

It is possible for the snprintf call to use a size value larger than the
size of the string. This should not cause a buffer overrun as it is
written now due to the value for the string format "%03lu" can not be
larger than 1000. However, this change makes it correct. By making the
size correct we guard against potential future changes that could actually
cause a buffer overrun.

Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
LKML-Reference: <1276619355-18116-1-git-send-email-chase.douglas@canonical.com>

[ added 'UL' to number 8 to fix gcc warning comparing it to sizeof() ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-28 21:11:39 -04:00
Li Zefan
67ead0a6ce tracing: Remove open-coded __trace_add_event_call()
Let trace_module_add_events() and event_trace_init() call
__trace_add_event_call().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BFA37E9.1020106@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-28 17:12:55 -04:00
Li Zefan
ffb9f99528 tracing: Remove redundant raw_init callbacks
raw_init callback is optional.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BFA37D4.7070500@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-28 17:12:53 -04:00
Li Zefan
c9d932cf8a tracing: Remove test of NULL define_fields callback
Every event (or event class) has it's define_fields callback,
so the test is redundant.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BFA37BC.8080707@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-28 17:12:52 -04:00
Li Zefan
8728fe501e tracing: Don't allocate common fields for every trace events
Every event has the same common fields, so it's a big waste of
memory to have a copy of those fields for every event.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BFA3759.30105@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-28 17:12:46 -04:00
Li Zefan
c9642c49aa tracing: Use a global field list for all syscall exit events
All syscall exit events have the same fields.

The kernel size drops 2.5K:

   text    data     bss     dec     hex filename
7018612 2034376 7251132 16304120         f8c7f8 vmlinux.o.orig
7018612 2031888 7251132 16301632         f8be40 vmlinux.o

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BFA3746.8070100@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-28 17:12:44 -04:00
Thomas Gleixner
f384c954c9 Merge branch 'linus' into perf/core
Reason: Further changes conflict with upstream fixes

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-06-28 22:33:24 +02:00
Steven Rostedt
a8fb260805 perf/tracing: Fix regression of perf losing kprobe events
With the addition of the code to shrink the kernel tracepoint
infrastructure, we lost kprobes being traced by perf. The reason
is that I tested if the "tp_event->class->perf_probe" existed before
enabling it. This prevents "ftrace only" events (like the function
trace events) from being enabled by perf.

Unfortunately, kprobe events do not use perf_probe. This causes
kprobes to be missed by perf. To fix this, we add the test to
see if "tp_event->class->reg" exists as well as perf_probe.

Normal trace events have only "perf_probe" but no "reg" function,
and kprobes and syscalls have the "reg" but no "perf_probe".
The ftrace unique events do not have either, so this is a valid
test. If a kprobe or syscall is not to be probed by perf, the
"reg" function is called anyway, and will return a failure and
prevent perf from probing it.

Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-10 20:56:54 -04:00
Ingo Molnar
c726b61c6a Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/core 2010-06-09 18:55:57 +02:00
Li Zefan
039ca4e74a tracing: Remove kmemtrace ftrace plugin
We have been resisting new ftrace plugins and removing existing
ones, and kmemtrace has been superseded by kmem trace events
and perf-kmem, so we remove it.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
[ remove kmemtrace from the makefile, handle slob too ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-06-09 17:31:22 +02:00
Peter Zijlstra
c676329abb sched_clock: Add local_clock() API and improve documentation
For people who otherwise get to write: cpu_clock(smp_processor_id()),
there is now: local_clock().

Also, as per suggestion from Andrew, provide some documentation on
the various clock interfaces, and minimize the unsigned long long vs
u64 mess.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jens Axboe <jaxboe@fusionio.com>
LKML-Reference: <1275052414.1645.52.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09 10:34:49 +02:00
Américo Wang
30dbb20e68 tracing: Remove boot tracer
The boot tracer is useless. It simply logs the initcalls
but in fact these initcalls are also logged through printk
while using the initcall_debug kernel parameter.

Nobody seem to be using it so far. Then just remove it.

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Chase Douglas <chase.douglas@canonical.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <20100526105753.GA5677@cr0.nay.redhat.com>
[ remove the hooks in main.c, and the headers ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-06-08 23:31:28 +02:00
Frederic Weisbecker
b0f82b81fe perf: Drop the skip argument from perf_arch_fetch_regs_caller
Drop this argument now that we always want to rewind only to the
state of the first caller.
It means frame pointers are not necessary anymore to reliably get
the source of an event. But this also means we need this helper
to be a macro now, as an inline function is not an option since
we need to know when to provide a default implentation.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-06-08 23:31:27 +02:00
Frederic Weisbecker
c9cf4dbb4d x86: Unify dumpstack.h and stacktrace.h
arch/x86/include/asm/stacktrace.h and arch/x86/kernel/dumpstack.h
declare headers of objects that deal with the same topic.
Actually most of the files that include stacktrace.h also include
dumpstack.h

Although dumpstack.h seems more reserved for internals of stack
traces, those are quite often needed to define specialized stack
trace operations. And perf event arch headers are going to need
access to such low level operations anyway. So don't continue to
bother with dumpstack.h as it's not anymore about isolated deep
internals.

v2: fix struct stack_frame definition conflict in sysprof

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Soeren Sandmann <sandmann@daimi.au.dk>
2010-06-08 23:29:52 +02:00
Ingo Molnar
6113e45f83 Merge branch 'tip/perf/core-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core 2010-06-08 19:34:40 +02:00
Steven Rostedt
5168ae50a6 tracing: Remove ftrace_preempt_disable/enable
The ftrace_preempt_disable/enable functions were to address a
recursive race caused by the function tracer. The function tracer
traces all functions which makes it easily susceptible to recursion.
One area was preempt_enable(). This would call the scheduler and
the schedulre would call the function tracer and loop.
(So was it thought).

The ftrace_preempt_disable/enable was made to protect against recursion
inside the scheduler by storing the NEED_RESCHED flag. If it was
set before the ftrace_preempt_disable() it would not call schedule
on ftrace_preempt_enable(), thinking that if it was set before then
it would have already scheduled unless it was already in the scheduler.

This worked fine except in the case of SMP, where another task would set
the NEED_RESCHED flag for a task on another CPU, and then kick off an
IPI to trigger it. This could cause the NEED_RESCHED to be saved at
ftrace_preempt_disable() but the IPI to arrive in the the preempt
disabled section. The ftrace_preempt_enable() would not call the scheduler
because the flag was already set before entring the section.

This bug would cause a missed preemption check and cause lower latencies.

Investigating further, I found that the recusion caused by the function
tracer was not due to schedule(), but due to preempt_schedule(). Now
that preempt_schedule is completely annotated with notrace, the recusion
no longer is an issue.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-03 19:32:38 -04:00
Randy Dunlap
546cf44a1b blktrace: Fix new kernel-doc warnings
Fix blktrace.c kernel-doc warnings:
 Warning(kernel/trace/blktrace.c:858): No description found for parameter 'ignore'
 Warning(kernel/trace/blktrace.c:890): No description found for parameter 'ignore'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100529114507.c466fc1e.randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-31 09:58:20 +02:00
Peter Zijlstra
2e97942fe5 perf_events, trace: Fix perf_trace_destroy(), mutex went missing
Steve spotted I forgot to do the destroy under event_mutex.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1274451913.1674.1707.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-31 08:46:09 +02:00
Peter Zijlstra
3771f07711 perf_events, trace: Fix probe unregister race
tracepoint_probe_unregister() does not synchronize against the probe
callbacks, so do that explicitly. This properly serializes the callbacks
and the free of the data used therein.

Also, use this_cpu_ptr() where possible.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1274438476.1674.1702.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-31 08:46:09 +02:00
Linus Torvalds
bc7d352c5e Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf tui: Fix last use_browser problem related to .perfconfig
  perf symbols: Add the build id cache to the vmlinux path
  perf tui: Reset use_browser if stdout is not a tty
  ring-buffer: Move zeroing out excess in page to ring buffer code
  ring-buffer: Reset "real_end" when page is filled
2010-05-30 12:35:01 -07:00
Linus Torvalds
c5617b200a Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (61 commits)
  tracing: Add __used annotation to event variable
  perf, trace: Fix !x86 build bug
  perf report: Support multiple events on the TUI
  perf annotate: Fix up usage of the build id cache
  x86/mmiotrace: Remove redundant instruction prefix checks
  perf annotate: Add TUI interface
  perf tui: Remove annotate from popup menu after failure
  perf report: Don't start the TUI if -D is used
  perf: Fix getline undeclared
  perf: Optimize perf_tp_event_match()
  perf: Remove more code from the fastpath
  perf: Optimize the !vmalloc backed buffer
  perf: Optimize perf_output_copy()
  perf: Fix wakeup storm for RO mmap()s
  perf-record: Share per-cpu buffers
  perf-record: Remove -M
  perf: Ensure that IOC_OUTPUT isn't used to create multi-writer buffers
  perf, trace: Optimize tracepoints by using per-tracepoint-per-cpu hlist to track events
  perf, trace: Optimize tracepoints by removing IRQ-disable from perf/tracepoint interaction
  perf tui: Allow disabling the TUI on a per command basis in ~/.perfconfig
  ...
2010-05-27 15:23:47 -07:00
Steven Rostedt
2711ca237a ring-buffer: Move zeroing out excess in page to ring buffer code
Currently the trace splice code zeros out the excess bytes in the page before
sending it off to userspace.

This is to make sure userspace is not getting anything it should not be
when reading the pages, because the excess data was never initialized
to zero before writing (for perfomance reasons).

But the splice code has no business in doing this work, it should be
done by the ring buffer. With the latest changes for recording lost
events, the splice code gets it wrong anyway.

Move the zeroing out of excess bytes into the ring buffer code.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-25 11:57:26 -04:00
Steven Rostedt
b3230c8b44 ring-buffer: Reset "real_end" when page is filled
The code to store the "lost events" requires knowing the real end
of the page. Since the 'commit' includes the padding at the end of
a page a "real_end" variable was used to keep track of the end not
including the padding.

If events were lost, the reader can place the count of events in
the padded area if there is enough room.

The bug this patch fixes is that when we fill the page we do not
reset the real_end variable, and if the writer had wrapped a few
times, the real_end would be incorrect.

This patch simply resets the real_end if the page was filled.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-25 11:57:24 -04:00
Peter Zijlstra
87f44bbc24 perf, trace: Fix !x86 build bug
Patch b7e2ecef92 (perf, trace: Optimize tracepoints by removing
IRQ-disable from perf/tracepoint interaction) made the
unfortunate mistake of assuming the world is x86 only, correct
this.

The problem was that perf_fetch_caller_regs() did
local_save_flags() into regs->flags, and I re-used that to
remove another local_save_flags(), forgetting !x86 doesn't have
regs->flags.

Do the reverse, remove the local_save_flags() from
perf_fetch_caller_regs() and let the ftrace site do the
local_save_flags() instead.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: acme@redhat.com
Cc: efault@gmx.de
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1274778175.5882.623.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-25 11:28:49 +02:00
Jens Axboe
ee9a3607fb Merge branch 'master' into for-2.6.35
Conflicts:
	fs/ext3/fsync.c

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 21:27:26 +02:00
Jens Axboe
35f3d14dbb pipe: add support for shrinking and growing pipes
This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for
growing and shrinking the size of a pipe and adjusts pipe.c and splice.c
(and relay and network splice) usage to work with these larger (or smaller)
pipes.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 21:12:40 +02:00
Steven Rostedt
ff5f149b6a Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into trace/tip/tracing/core-7
Conflicts:
	include/linux/ftrace_event.h
	include/trace/ftrace.h
	kernel/trace/trace_event_perf.c
	kernel/trace/trace_kprobe.c
	kernel/trace/trace_syscalls.c

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-21 11:49:57 -04:00
Linus Torvalds
33cf23b0a5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (182 commits)
  [SCSI] aacraid: add an ifdef'd device delete case instead of taking the device offline
  [SCSI] aacraid: prohibit access to array container space
  [SCSI] aacraid: add support for handling ATA pass-through commands.
  [SCSI] aacraid: expose physical devices for models with newer firmware
  [SCSI] aacraid: respond automatically to volumes added by config tool
  [SCSI] fcoe: fix fcoe module ref counting
  [SCSI] libfcoe: FIP Keep-Alive messages for VPorts are sent with incorrect port_id and wwn
  [SCSI] libfcoe: Fix incorrect MAC address clearing
  [SCSI] fcoe: fix a circular locking issue with rtnl and sysfs mutex
  [SCSI] libfc: Move the port_id into lport
  [SCSI] fcoe: move link speed checking into its own routine
  [SCSI] libfc: Remove extra pointer check
  [SCSI] libfc: Remove unused fc_get_host_port_type
  [SCSI] fcoe: fixes wrong error exit in fcoe_create
  [SCSI] libfc: set seq_id for incoming sequence
  [SCSI] qla2xxx: Updates to ISP82xx support.
  [SCSI] qla2xxx: Optionally disable target reset.
  [SCSI] qla2xxx: ensure flash operation and host reset via sg_reset are mutually exclusive
  [SCSI] qla2xxx: Silence bogus warning by gcc for wrap and did.
  [SCSI] qla2xxx: T10 DIF support added.
  ...
2010-05-21 07:19:18 -07:00
Peter Zijlstra
1c024eca51 perf, trace: Optimize tracepoints by using per-tracepoint-per-cpu hlist to track events
Avoid the swevent hash-table by using per-tracepoint
hlists.

Also, avoid conditionals on the fast path by ordering
with probe unregister so that we should never get on
the callback path without the data being there.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.473188012@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-21 11:37:56 +02:00
Peter Zijlstra
b7e2ecef92 perf, trace: Optimize tracepoints by removing IRQ-disable from perf/tracepoint interaction
Improves performance.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1274259525.5605.10352.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-21 11:37:56 +02:00
Ingo Molnar
dfacc4d6c9 Merge branch 'perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/core 2010-05-20 14:38:55 +02:00
Peter Zijlstra
4f41c013f5 perf/ftrace: Optimize perf/tracepoint interaction for single events
When we've got but a single event per tracepoint
there is no reason to try and multiplex it so don't.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 18:35:46 +02:00
Linus Torvalds
752f114fb8 Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing: Fix "integer as NULL pointer" warning.
  tracing: Fix tracepoint.h DECLARE_TRACE() to allow more than one header
  tracing: Make the documentation clear on trace_event boot option
  ring-buffer: Wrap open-coded WARN_ONCE
  tracing: Convert nop macros to static inlines
  tracing: Fix sleep time function profiling
  tracing: Show sample std dev in function profiling
  tracing: Add documentation for trace commands mod, traceon/traceoff
  ring-buffer: Make benchmark handle missed events
  ring-buffer: Make non-consuming read less expensive with lots of cpus.
  tracing: Add graph output support for irqsoff tracer
  tracing: Have graph flags passed in to ouput functions
  tracing: Add ftrace events for graph tracer
  tracing: Dump either the oops's cpu source or all cpus buffers
  tracing: Fix uninitialized variable of tracing/trace output
2010-05-18 08:35:04 -07:00
Linus Torvalds
b8ae30ee26 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits)
  stop_machine: Move local variable closer to the usage site in cpu_stop_cpu_callback()
  sched, wait: Use wrapper functions
  sched: Remove a stale comment
  ondemand: Make the iowait-is-busy time a sysfs tunable
  ondemand: Solve a big performance issue by counting IOWAIT time as busy
  sched: Intoduce get_cpu_iowait_time_us()
  sched: Eliminate the ts->idle_lastupdate field
  sched: Fold updating of the last_update_time_info into update_ts_time_stats()
  sched: Update the idle statistics in get_cpu_idle_time_us()
  sched: Introduce a function to update the idle statistics
  sched: Add a comment to get_cpu_idle_time_us()
  cpu_stop: add dummy implementation for UP
  sched: Remove rq argument to the tracepoints
  rcu: need barrier() in UP synchronize_sched_expedited()
  sched: correctly place paranioa memory barriers in synchronize_sched_expedited()
  sched: kill paranoia check in synchronize_sched_expedited()
  sched: replace migration_thread with cpu_stop
  stop_machine: reimplement using cpu_stop
  cpu_stop: implement stop_cpu[s]()
  sched: Fix select_idle_sibling() logic in select_task_rq_fair()
  ...
2010-05-18 08:27:54 -07:00
Linus Torvalds
4d7b4ac22f Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (311 commits)
  perf tools: Add mode to build without newt support
  perf symbols: symbol inconsistency message should be done only at verbose=1
  perf tui: Add explicit -lslang option
  perf options: Type check all the remaining OPT_ variants
  perf options: Type check OPT_BOOLEAN and fix the offenders
  perf options: Check v type in OPT_U?INTEGER
  perf options: Introduce OPT_UINTEGER
  perf tui: Add workaround for slang < 2.1.4
  perf record: Fix bug mismatch with -c option definition
  perf options: Introduce OPT_U64
  perf tui: Add help window to show key associations
  perf tui: Make <- exit menus too
  perf newt: Add single key shortcuts for zoom into DSO and threads
  perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed
  perf newt: Fix the 'A'/'a' shortcut for annotate
  perf newt: Make <- exit the ui_browser
  x86, perf: P4 PMU - fix counters management logic
  perf newt: Make <- zoom out filters
  perf report: Report number of events, not samples
  perf hist: Clarify events_stats fields usage
  ...

Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c
2010-05-18 08:19:03 -07:00
Steven Rostedt
f0218b3e99 Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into trace/tip/tracing/core-6
Conflicts:
	include/trace/ftrace.h
	kernel/trace/trace_kprobe.c

Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-18 00:35:23 -04:00
Li Zefan
e1f7992e01 tracing: Fix function declarations if !CONFIG_STACKTRACE
ftrace_trace_stack() and frace_trace_userstacke() take a
struct ring_buffer argument, not struct trace_array. Commit
e77405ad("tracing: pass around ring buffer instead of tracer")
made this change.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BE77C14.5010806@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:33:24 -04:00
Steven Rostedt
553552ce17 tracing: Combine event filter_active and enable into single flags field
The filter_active and enable both use an int (4 bytes each) to
set a single flag. We can save 4 bytes per event by combining the
two into a single integer.

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4894944	1018052	 861512	6774508	 675eec	vmlinux.id
4894871	1012292	 861512	6768675	 674823	vmlinux.flags

This gives us another 5K in savings.

The modification of both the enable and filter fields are done
under the event_mutex, so it is still safe to combine the two.

Note: Although Mathieu gave his Acked-by, he would like it documented
 that the reads of flags are not protected by the mutex. The way the
 code works, these reads will not break anything, but will have a
 residual effect. Since this behavior is the same even before this
 patch, describing this situation is left to another patch, as this
 patch does not change the behavior, but just brought it to Mathieu's
 attention.

v2: Updated the event trace self test to for this change.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:33:22 -04:00
Steven Rostedt
32c0edaeaa tracing: Remove duplicate id information in event structure
Now that the trace_event structure is embedded in the ftrace_event_call
structure, there is no need for the ftrace_event_call id field.
The id field is the same as the trace_event type field.

Removing the id and re-arranging the structure brings down the tracepoint
footprint by another 5K.

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4895024	1023812	 861512	6780348	 6775bc	vmlinux.print
4894944	1018052	 861512	6774508	 675eec	vmlinux.id

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:33:15 -04:00
Steven Rostedt
80decc70af tracing: Move print functions into event class
Currently, every event has its own trace_event structure. This is
fine since the structure is needed anyway. But the print function
structure (trace_event_functions) is now separate. Since the output
of the trace event is done by the class (with the exception of events
defined by DEFINE_EVENT_PRINT), it makes sense to have the class
define the print functions that all events in the class can use.

This makes a bigger deal with the syscall events since all syscall events
use the same class. The savings here is another 30K.

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4900382	1048964	 861512	6810858	 67ecea	vmlinux.init
4900446	1049028	 861512	6810986	 67ed6a	vmlinux.preprint
4895024	1023812	 861512	6780348	 6775bc	vmlinux.print

To accomplish this, and to let the class know what event is being
printed, the event structure is embedded in the ftrace_event_call
structure. This should not be an issues since the event structure
was created for each event anyway.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:20:34 -04:00
Steven Rostedt
a9a5776380 tracing: Allow events to share their print functions
Multiple events may use the same method to print their data.
Instead of having all events have a pointer to their print funtions,
the trace_event structure now points to a trace_event_functions structure
that will hold the way to print ouf the event.

The event itself is now passed to the print function to let the print
function know what kind of event it should print.

This opens the door to consolidating the way several events print
their output.

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4900382	1048964	 861512	6810858	 67ecea	vmlinux.init
4900446	1049028	 861512	6810986	 67ed6a	vmlinux.preprint

This change slightly increases the size but is needed for the next change.

v3: Fix the branch tracer events to handle this change.

v2: Fix the new function graph tracer event calls to handle this change.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:20:32 -04:00
Steven Rostedt
0405ab80aa tracing: Move raw_init from events to class
The raw_init function pointer in the event is used to initialize
various kinds of events. The type of initialization needed is usually
classed to the kind of event it is.

Two events with the same class will always have the same initialization
function, so it makes sense to move this to the class structure.

Perhaps even making a special system structure would work since
the initialization is the same for all events within a system.
But since there's no system structure (yet), this will just move it
to the class.

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4900375	1053380	 861512	6815267	 67fe23	vmlinux.fields
4900382	1048964	 861512	6810858	 67ecea	vmlinux.init

The text grew very slightly, but this is a constant growth that happened
with the changing of the C files that call the init code.
The bigger savings is the data which will be saved the more events share
a class.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:20:30 -04:00
Steven Rostedt
2e33af0295 tracing: Move fields from event to class structure
Move the defined fields from the event to the class structure.
Since the fields of the event are defined by the class they belong
to, it makes sense to have the class hold the information instead
of the individual events. The events of the same class would just
hold duplicate information.

After this change the size of the kernel dropped another 3K:

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4900252	1057412	 861512	6819176	 680d68	vmlinux.regs
4900375	1053380	 861512	6815267	 67fe23	vmlinux.fields

Although the text increased, this was mainly due to the C files
having to adapt to the change. This is a constant increase, where
new tracepoints will not increase the Text. But the big drop is
in the data size (as well as needed allocations to hold the fields).
This will give even more savings as more tracepoints are created.

Note, if just TRACE_EVENT()s are used and not DECLARE_EVENT_CLASS()
with several DEFINE_EVENT()s, then the savings will be lost. But
we are pushing developers to consolidate events with DEFINE_EVENT()
so this should not be an issue.

The kprobes define a unique class to every new event, but are dynamic
so it should not be a issue.

The syscalls however have a single class but the fields for the individual
events are different. The syscalls use a metadata to define the
fields. I moved the fields list from the event to the metadata and
added a "get_fields()" function to the class. This function is used
to find the fields. For normal events and kprobes, get_fields() just
returns a pointer to the fields list_head in the class. For syscall
events, it returns the fields list_head in the metadata for the event.

v2:  Fixed the syscall fields. The syscall metadata needs a list
     of fields for both enter and exit.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:20:23 -04:00
Steven Rostedt
2239291aeb tracing: Remove per event trace registering
This patch removes the register functions of TRACE_EVENT() to enable
and disable tracepoints. The registering of a event is now down
directly in the trace_events.c file. The tracepoint_probe_register()
is now called directly.

The prototypes are no longer type checked, but this should not be
an issue since the tracepoints are created automatically by the
macros. If a prototype is incorrect in the TRACE_EVENT() macro, then
other macros will catch it.

The trace_event_class structure now holds the probes to be called
by the callbacks. This removes needing to have each event have
a separate pointer for the probe.

To handle kprobes and syscalls, since they register probes in a
different manner, a "reg" field is added to the ftrace_event_class
structure. If the "reg" field is assigned, then it will be called for
enabling and disabling of the probe for either ftrace or perf. To let
the reg function know what is happening, a new enum (trace_reg) is
created that has the type of control that is needed.

With this new rework, the 82 kernel events and 618 syscall events
has their footprint dramatically lowered:

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4914025	1088868	 861512	6864405	 68be15	vmlinux.class
4918492	1084612	 861512	6864616	 68bee8	vmlinux.tracepoint
4900252	1057412	 861512	6819176	 680d68	vmlinux.regs

The size went from 6863829 to 6819176, that's a total of 44K
in savings. With tracepoints being continuously added, this is
critical that the footprint becomes minimal.

v5: Added #ifdef CONFIG_PERF_EVENTS around a reference to perf
    specific structure in trace_events.c.

v4: Fixed trace self tests to check probe because regfunc no longer
    exists.

v3: Updated to handle void *data in beginning of probe parameters.
    Also added the tracepoint: check_trace_callback_type_##call().

v2: Changed the callback probes to pass void * and typecast the
    value within the function.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 14:19:14 -04:00
Steven Rostedt
38516ab59f tracing: Let tracepoints have data passed to tracepoint callbacks
This patch adds data to be passed to tracepoint callbacks.

The created functions from DECLARE_TRACE() now need a mandatory data
parameter. For example:

DECLARE_TRACE(mytracepoint, int value, value)

Will create the register function:

int register_trace_mytracepoint((void(*)(void *data, int value))probe,
                                void *data);

As the first argument, all callbacks (probes) must take a (void *data)
parameter. So a callback for the above tracepoint will look like:

void myprobe(void *data, int value)
{
}

The callback may choose to ignore the data parameter.

This change allows callbacks to register a private data pointer along
with the function probe.

	void mycallback(void *data, int value);

	register_trace_mytracepoint(mycallback, mydata);

Then the mycallback() will receive the "mydata" as the first parameter
before the args.

A more detailed example:

  DECLARE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status));

  /* In the C file */

  DEFINE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status));

  [...]

       trace_mytracepoint(status);

  /* In a file registering this tracepoint */

  int my_callback(void *data, int status)
  {
	struct my_struct my_data = data;
	[...]
  }

  [...]
	my_data = kmalloc(sizeof(*my_data), GFP_KERNEL);
	init_my_data(my_data);
	register_trace_mytracepoint(my_callback, my_data);

The same callback can also be registered to the same tracepoint as long
as the data registered is different. Note, the data must also be used
to unregister the callback:

	unregister_trace_mytracepoint(my_callback, my_data);

Because of the data parameter, tracepoints declared this way can not have
no args. That is:

  DECLARE_TRACE(mytracepoint, TP_PROTO(void), TP_ARGS());

will cause an error.

If no arguments are needed, a new macro can be used instead:

  DECLARE_TRACE_NOARGS(mytracepoint);

Since there are no arguments, the proto and args fields are left out.

This is part of a series to make the tracepoint footprint smaller:

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4914025	1088868	 861512	6864405	 68be15	vmlinux.class
4918492	1084612	 861512	6864616	 68bee8	vmlinux.tracepoint

Again, this patch also increases the size of the kernel, but
lays the ground work for decreasing it.

 v5: Fixed net/core/drop_monitor.c to handle these updates.

 v4: Moved the DECLARE_TRACE() DECLARE_TRACE_NOARGS out of the
     #ifdef CONFIG_TRACE_POINTS, since the two are the same in both
     cases. The __DECLARE_TRACE() is what changes.
     Thanks to Frederic Weisbecker for pointing this out.

 v3: Made all register_* functions require data to be passed and
     all callbacks to take a void * parameter as its first argument.
     This makes the calling functions comply with C standards.

     Also added more comments to the modifications of DECLARE_TRACE().

 v2: Made the DECLARE_TRACE() have the ability to pass arguments
     and added a new DECLARE_TRACE_NOARGS() for tracepoints that
     do not need any arguments.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 09:50:34 -04:00
Steven Rostedt
8f08201830 tracing: Create class struct for events
This patch creates a ftrace_event_class struct that event structs point to.
This class struct will be made to hold information to modify the
events. Currently the class struct only holds the events system name.

This patch slightly increases the size, but this change lays the ground work
of other changes to make the footprint of tracepoints smaller.

With 82 standard tracepoints, and 618 system call tracepoints
(two tracepoints per syscall: enter and exit):

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4914025	1088868	 861512	6864405	 68be15	vmlinux.class

This patch also cleans up some stale comments in ftrace.h.

v2: Fixed missing semi-colon in macro.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-14 09:33:49 -04:00
Steven Rostedt
23e117fa44 Merge branch 'sched/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into trace/tip/tracing/core-4 2010-05-14 09:29:52 -04:00
Peter Zijlstra
27a9da6538 sched: Remove rq argument to the tracepoints
struct rq isn't visible outside of sched.o so its near useless to
expose the pointer, also there are no users of it, so remove it.

Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1272997616.1642.207.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-07 11:28:17 +02:00
Dan Carpenter
d9f599e1e6 perf: Fix check at end of event search
The original code doesn't work because "call" is never NULL there.

Signed-off-by: Dan Carpenter <error27@gmail.com>
LKML-Reference: <20100320143911.GF5331@bicker>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-06 19:49:52 -04:00
Thiago Farina
668eb65f09 tracing: Fix "integer as NULL pointer" warning.
kernel/trace/trace_output.c:256:24: warning: Using plain integer as NULL pointer

Signed-off-by: Thiago Farina <tfransosi@gmail.com>
LKML-Reference: <1264349038-1766-3-git-send-email-tfransosi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-05 12:01:26 -04:00
Borislav Petkov
956097912c ring-buffer: Wrap open-coded WARN_ONCE
Wrap open-coded WARN_ONCE functionality into the equivalent macro.

Signed-off-by: Borislav Petkov <bp@alien8.de>
LKML-Reference: <20100502060354.GA5281@liondog.tnic>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-04 12:23:47 -04:00
Frederic Weisbecker
feef47d0cb hw-breakpoints: Get the number of available registers on boot dynamically
The breakpoint generic layer assumes that archs always know in advance
the static number of address registers available to host breakpoints
through the HBP_NUM macro.

However this is not true for every archs. For example Arm needs to get
this information dynamically to handle the compatiblity between
different versions.

To solve this, this patch proposes to drop the static HBP_NUM macro
and let the arch provide the number of available slots through a
new hw_breakpoint_slots() function. For archs that have
CONFIG_HAVE_MIXED_BREAKPOINTS_REGS selected, it will be called once
as the number of registers fits for instruction and data breakpoints
together.
For the others it will be called first to get the number of
instruction breakpoint registers and another time to get the
data breakpoint registers, the targeted type is given as a
parameter of hw_breakpoint_slots().

Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: K. Prasad <prasad@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-05-01 04:32:14 +02:00
Kei Tokunaga
bf81623542 [SCSI] add scsi trace core functions and put trace points
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@jp.fujitsu.com>
Signed-off-by: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-04-30 12:51:10 -05:00
Kei Tokunaga
5a2e399595 [SCSI] ftrace: add __print_hex()
__print_hex() prints values in an array in hex (w/o '0x') (space separated)
EX) 92 33 32 f3 ee 4d

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@jp.fujitsu.com>
Signed-off-by: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-04-30 12:50:22 -05:00
Steven Rostedt
37e44bc50d tracing: Fix sleep time function profiling
When sleep_time is off the function profiler ignores the time that a task
is scheduled out. When the task is scheduled out a timestamp is taken.
When the task is scheduled back in, the timestamp is compared to the
current time and the saved calltimes are adjusted accordingly.

But when stopping the function profiler, the sched switch hook that
does this adjustment was stopped before shutting down the tracer.
This allowed some tasks to not get their timestamps set when they
scheduled out. When the function profiler started again, this would
skew the times of the scheduler functions.

This patch moves the stopping of the sched switch to after the function
profiler is stopped. It also ignores zero set calltimes, which may
happen on start up.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-04-27 21:04:24 -04:00
Chase Douglas
e330b3bcd8 tracing: Show sample std dev in function profiling
When combined with function graph tracing the ftrace function profiler
also prints the average run time of functions. While this gives us some
good information, it doesn't tell us anything about the variance of the
run times of the function. This change prints out the s^2 sample
standard deviation alongside the average.

This change adds one entry to the profile record structure. This
increases the memory footprint of the function profiler by 1/3 on a
32-bit system, and by 1/5 on a 64-bit system when function graphing is
enabled, though the memory is only allocated when the profiler is turned
on. During the profiling, one extra line of code adds the squared
calltime to the new record entry, so this should not adversly affect
performance.

Note that the square of the sample standard deviation is printed because
there is no sqrt implementation for unsigned long long in the kernel.

Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
LKML-Reference: <1272304925-2436-1-git-send-email-chase.douglas@canonical.com>

[ fixed comment about ns^2 -> us^2 conversion ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-04-27 18:23:15 -04:00
Steven Rostedt
a838b2e634 ring-buffer: Make benchmark handle missed events
With the addition of the "missed events" flags that is stored in the
commit field of the ring buffer page, the ring_buffer_benchmark
was not updated to handle this. If events are missed, then the
missed events flag is set in the ring buffer page, the benchmark
will count that flag as part of the size of the page and will hit the BUG()
when it tries to read beyond the page.

The solution is simply to have the ring buffer benchmark mask off
the extra bits.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-04-27 13:26:58 -04:00
David Miller
72c9ddfd4c ring-buffer: Make non-consuming read less expensive with lots of cpus.
When performing a non-consuming read, a synchronize_sched() is
performed once for every cpu which is actively tracing.

This is very expensive, and can make it take several seconds to open
up the 'trace' file with lots of cpus.

Only one synchronize_sched() call is actually necessary.  What is
desired is for all cpus to see the disabling state change.  So we
transform the existing sequence:

	for_each_cpu() {
		ring_buffer_read_start();
	}

where each ring_buffer_start() call performs a synchronize_sched(),
into the following:

	for_each_cpu() {
		ring_buffer_read_prepare();
	}
	ring_buffer_read_prepare_sync();
	for_each_cpu() {
		ring_buffer_read_start();
	}

wherein only the single ring_buffer_read_prepare_sync() call needs to
do the synchronize_sched().

The first phase, via ring_buffer_read_prepare(), allocates the 'iter'
memory and increments ->record_disabled.

In the second phase, ring_buffer_read_prepare_sync() makes sure this
->record_disabled state is visible fully to all cpus.

And in the final third phase, the ring_buffer_read_start() calls reset
the 'iter' objects allocated in the first phase since we now know that
none of the cpus are adding trace entries any more.

This makes openning the 'trace' file nearly instantaneous on a
sparc64 Niagara2 box with 128 cpus tracing.

Signed-off-by: David S. Miller <davem@davemloft.net>
LKML-Reference: <20100420.154711.11246950.davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-04-27 13:06:35 -04:00
Jiri Olsa
62b915f106 tracing: Add graph output support for irqsoff tracer
Add function graph output to irqsoff tracer.

The graph output is enabled by setting new 'display-graph' trace option.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1270227683-14631-4-git-send-email-jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-04-27 12:36:53 -04:00
Jiri Olsa
d7a8d9e907 tracing: Have graph flags passed in to ouput functions
Let the function graph tracer have custom flags passed to its
output functions.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1270227683-14631-3-git-send-email-jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-04-26 17:30:18 -04:00
Jiri Olsa
9106b69382 tracing: Add ftrace events for graph tracer
Add ftrace events for graph tracer, so the graph output could be shared
with other tracers.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1270227683-14631-2-git-send-email-jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-04-26 16:55:08 -04:00
Frederic Weisbecker
cecbca96da tracing: Dump either the oops's cpu source or all cpus buffers
The ftrace_dump_on_oops kernel parameter, sysctl and sysrq let one
dump every cpu buffers when an oops or panic happens.

It's nice when you have few cpus but it may take ages if have many,
plus you miss the real origin of the problem in all the cpu traces.

Sometimes, all you need is to dump the cpu buffer that triggered the
opps, most of the time it is our main interest.

This patch modifies ftrace_dump_on_oops to handle this choice.

The ftrace_dump_on_oops kernel parameter, when it comes alone, has
the same behaviour than before. But ftrace_dump_on_oops=orig_cpu
will only dump the buffer of the cpu that oops'ed.

Similarly, sysctl kernel.ftrace_dump_on_oops=1 and
echo 1 > /proc/sys/kernel/ftrace_dump_on_oops keep their previous
behaviour. But setting 2 jumps into cpu origin dump mode.

v2: Fix double setup
v3: Fix spelling issues reported by Randy Dunlap
v4: Also update __ftrace_dump in the selftests

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
2010-04-21 23:11:42 +02:00
Masami Hiramatsu
93ccae7a22 tracing/kprobes: Support basic types on dynamic events
Support basic types of integer (u8, u16, u32, u64, s8, s16, s32, s64) in
kprobe tracer. With this patch, users can specify above basic types on
each arguments after ':'. If omitted, the argument type is set as
unsigned long (u32 or u64, arch-dependent).

 e.g.
  echo 'p account_system_time+0 hardirq_offset=%si:s32' > kprobe_events

  adds a probe recording hardirq_offset in signed-32bits value on the
  entry of account_system_time.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100412171708.3790.18599.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-04-14 17:26:28 -03:00
Ingo Molnar
b15c7b1cee Merge branch 'tip/tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/core 2010-04-14 12:15:23 +02:00
Ingo Molnar
ca7e0c6120 Merge branch 'linus' into perf/core
Semantic conflict: arch/x86/kernel/cpu/perf_event_intel_ds.c

Merge reason: pick up latest fixes, fix the conflict

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-08 13:37:18 +02:00
Ingo Molnar
c1ab9cab75 Merge branch 'linus' into tracing/core
Conflicts:
	include/linux/module.h
	kernel/module.c

Semantic conflict:
	include/trace/events/module.h

Merge reason: Resolve the conflict with upstream commit 5fbfb18 ("Fix up
              possibly racy module refcounting")

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-08 10:18:47 +02:00
Lai Jiangshan
aa27497c2f tracing: Fix uninitialized variable of tracing/trace output
Because a local variable is not initialized, I got these
when I did 'cat tracing/trace'. (not trace_pipe):

CPU:0 [LOST 18446744071579453134 EVENTS]
              ps-3099  [000]   560.770221: lock_acquire: ffff880030865010 &(&dentry->d_lock)->rlock
CPU:0 [LOST 18446744071579453134 EVENTS]
              ps-3099  [000]   560.770221: lock_release: ffff880030865010 &(&dentry->d_lock)->rlock
CPU:0 [LOST 18446612133255294080 EVENTS]
              ps-3099  [000]   560.770221: lock_acquire: ffff880030865010 &(&dentry->d_lock)->rlock
CPU:0 [LOST 18446744071579453134 EVENTS]
              ps-3099  [000]   560.770222: lock_release: ffff880030865010 &(&dentry->d_lock)->rlock
CPU:0 [LOST 18446744071579453134 EVENTS]
              ps-3099  [000]   560.770222: lock_release: ffffffff816cfb98 dcache_lock

See peek_next_entry(), it does not set *lost_events when we 'cat tracing/trace'

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4BB9A929.2000303@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-04-05 11:01:22 -04:00
Tejun Heo
336f5899d2 Merge branch 'master' into export-slabh 2010-04-05 11:37:28 +09:00
Linus Torvalds
8ce42c8b7f Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf: Always build the powerpc perf_arch_fetch_caller_regs version
  perf: Always build the stub perf_arch_fetch_caller_regs version
  perf, probe-finder: Build fix on Debian
  perf/scripts: Tuple was set from long in both branches in python_process_event()
  perf: Fix 'perf sched record' deadlock
  perf, x86: Fix callgraphs of 32-bit processes on 64-bit kernels
  perf, x86: Fix AMD hotplug & constraint initialization
  x86: Move notify_cpu_starting() callback to a later stage
  x86,kgdb: Always initialize the hw breakpoint attribute
  perf: Use hot regs with software sched switch/migrate events
  perf: Correctly align perf event tracing buffer
2010-04-04 12:13:10 -07:00
Ingo Molnar
ec5e61aabe Merge branch 'perf/urgent' into perf/core
Conflicts:
	arch/x86/kernel/cpu/perf_event.c

Merge reason: Resolve the conflict, pick up fixes

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 19:38:10 +02:00
Frederic Weisbecker
eb1e79611c perf: Correctly align perf event tracing buffer
The trace event buffer used by perf to record raw sample events
is typed as an array of char and may then not be aligned to 8
by alloc_percpu().

But we need it to be aligned to 8 in sparc64 because we cast
this buffer into a random structure type built by the TRACE_EVENT()
macro to store the traces. So if a random 64 bits field is accessed
inside, it may be not under an expected good alignment.

Use an array of long instead to force the appropriate alignment, and
perform a compile time check to ensure the size in byte of the buffer
is a multiple of sizeof(long) so that its actual size doesn't get
shrinked under us.

This fixes unaligned accesses reported while using perf lock
in sparc 64.

Suggested-by: David Miller <davem@davemloft.net>
Suggested-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
2010-04-01 08:26:30 +02:00
Steven Rostedt
ff0ff84a07 ring-buffer: Add lost event count to end of sub buffer
Currently, binary readers of the ring buffer only know where events were
lost, but not how many events were lost at that location.
This information is available, but it would require adding another
field to the sub buffer header to include it.

But when a event can not fit at the end of a sub buffer, it is written
to the next sub buffer. This means there is a good chance that the
buffer may have room to hold this counter. If it does, write
the counter at the end of the sub buffer and set another flag
in the data size field that states that this information exists.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-31 22:57:08 -04:00
Steven Rostedt
bc21b47842 tracing: Show the lost events in the trace_pipe output
Now that the ring buffer can keep track of where events are lost.
Use this information to the output of trace_pipe:

       hackbench-3588  [001]  1326.701660: lock_acquire: ffffffff816591e0 read rcu_read_lock
       hackbench-3588  [001]  1326.701661: lock_acquire: ffff88003f4091f0 &(&dentry->d_lock)->rlock
       hackbench-3588  [001]  1326.701664: lock_release: ffff88003f4091f0 &(&dentry->d_lock)->rlock
CPU:1 [LOST 673 EVENTS]
       hackbench-3588  [001]  1326.702711: kmem_cache_free: call_site=ffffffff81102b85 ptr=ffff880026d96738
       hackbench-3588  [001]  1326.702712: lock_release: ffff88003e1480a8 &mm->mmap_sem
       hackbench-3588  [001]  1326.702713: lock_acquire: ffff88003e1480a8 &mm->mmap_sem

Even works with the function graph tracer:

 2) ! 170.098 us  |                                            }
 2)   4.036 us    |                                            rcu_irq_exit();
 2)   3.657 us    |                                            idle_cpu();
 2) ! 190.301 us  |                                          }
CPU:2 [LOST 2196 EVENTS]
 2)   0.853 us    |                            } /* cancel_dirty_page */
 2)               |                            remove_from_page_cache() {
 2)   1.578 us    |                              _raw_spin_lock_irq();
 2)               |                              __remove_from_page_cache() {

Note, it does not work with the iterator "trace" file, since it requires
the use of consuming the page from the ring buffer to determine how many
events were lost, which the iterator does not do.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-31 22:57:06 -04:00
Steven Rostedt
66a8cb95ed ring-buffer: Add place holder recording of dropped events
Currently, when the ring buffer drops events, it does not record
the fact that it did so. It does inform the writer that the event
was dropped by returning a NULL event, but it does not put in any
place holder where the event was dropped.

This is not a trivial thing to add because the ring buffer mostly
runs in overwrite (flight recorder) mode. That is, when the ring
buffer is full, new data will overwrite old data.

In a produce/consumer mode, where new data is simply dropped when
the ring buffer is full, it is trivial to add the placeholder
for dropped events. When there's more room to write new data, then
a special event can be added to notify the reader about the dropped
events.

But in overwrite mode, any new write can overwrite events. A place
holder can not be inserted into the ring buffer since there never
may be room. A reader could also come in at anytime and miss the
placeholder.

Luckily, the way the ring buffer works, the read side can find out
if events were lost or not, and how many events. Everytime a write
takes place, if it overwrites the header page (the next read) it
updates a "overrun" variable that keeps track of the number of
lost events. When a reader swaps out a page from the ring buffer,
it can record this number, perfom the swap, and then check to
see if the number changed, and take the diff if it has, which would be
the number of events dropped. This can be stored by the reader
and returned to callers of the reader.

Since the reader page swap will fail if the writer moved the head
page since the time the reader page set up the swap, this gives room
to record the overruns without worrying about races. If the reader
sets up the pages, records the overrun, than performs the swap,
if the swap succeeds, then the overrun variable has not been
updated since the setup before the swap.

For binary readers of the ring buffer, a flag is set in the header
of each sub page (sub buffer) of the ring buffer. This flag is embedded
in the size field of the data on the sub buffer, in the 31st bit (the size
can be 32 or 64 bits depending on the architecture), but only 27
bits needs to be used for the actual size (less actually).

We could add a new field in the sub buffer header to also record the
number of events dropped since the last read, but this will change the
format of the binary ring buffer a bit too much. Perhaps this change can
be made if the information on the number of events dropped is considered
important enough.

Note, the notification of dropped events is only used by consuming reads
or peeking at the ring buffer. Iterating over the ring buffer does not
keep this information because the necessary data is only available when
a page swap is made, and the iterator does not swap out pages.

Cc: Robert Richter <robert.richter@amd.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "Luis Claudio R. Goncalves" <lclaudio@uudg.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-31 22:57:04 -04:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Julia Lawall
292f60c0c4 ring-buffer: Add missing unlock
In some error handling cases the lock is not unlocked.  The return is
converted to a goto, to share the unlock at the end of the function.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E1;
identifier f;
@@

f (...) { <+...
* spin_lock_irq (E1,...);
... when != E1
* return ...;
...+> }
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
LKML-Reference: <Pine.LNX.4.64.1003291736440.21896@ask.diku.dk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-29 15:23:24 -04:00
Li Zefan
e36673ec51 tracing: Fix lockdep warning in global_clock()
# echo 1 > events/enable
 # echo global > trace_clock

------------[ cut here ]------------
WARNING: at kernel/lockdep.c:3162 check_flags+0xb2/0x190()
...
---[ end trace 3f86734a89416623 ]---
possible reason: unannotated irqs-on.
...

There's no reason to use the raw_local_irq_save() in trace_clock_global.
The local_irq_save() version is fine, and does not cause the bug in lockdep.

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BA97FA1.7030606@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-29 15:16:44 -04:00
Linus Torvalds
833961d81f Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ring-buffer: Do 8 byte alignment for 64 bit that can not handle 4 byte align
2010-03-26 15:10:13 -07:00
Peter Zijlstra
faa4602e47 x86, perf, bts, mm: Delete the never used BTS-ptrace code
Support for the PMU's BTS features has been upstreamed in
v2.6.32, but we still have the old and disabled ptrace-BTS,
as Linus noticed it not so long ago.

It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without
regard for other uses (perf) and doesn't provide the flexibility
needed for perf either.

Its users are ptrace-block-step and ptrace-bts, since ptrace-bts
was never used and ptrace-block-step can be implemented using a
much simpler approach.

So axe all 3000 lines of it. That includes the *locked_memory*()
APIs in mm/mlock.c as well.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Markus Metzger <markus.t.metzger@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <20100325135413.938004390@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-26 11:33:55 +01:00
Steven Rostedt
2271048d1b ring-buffer: Do 8 byte alignment for 64 bit that can not handle 4 byte align
The ring buffer uses 4 byte alignment while recording events into the
buffer, even on 64bit machines. This saves space when there are lots
of events being recorded at 4 byte boundaries.

The ring buffer has a zero copy method to write into the buffer, with
the reserving of space and then committing it. This may cause problems
when writing an 8 byte word into a 4 byte alignment (not 8). For x86 and
PPC this is not an issue, but on some architectures this would cause an
out-of-alignment exception.

This patch uses CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to determine
if it is OK to use 4 byte alignments on 64 bit machines. If it is not,
it forces the ring buffer event header to be 8 bytes and not 4,
and will align the length of the data to be 8 byte aligned.
This keeps the data payload at 8 byte alignments and will allow these
machines to run without issue.

The trick to this is that the header can be either 4 bytes or 8 bytes
depending on the length of the data payload. The 4 byte header
has a length field that supports up to 112 bytes. If the length of
the data is more than 112, the length field is set to zero, and the actual
length is stored in the next 4 bytes after the header.

When CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is not set, the code forces
zero in the 4 byte header forcing the length to be stored in the 4 byte
array, even with a small data load. It also forces the length of the
data load to be 8 byte aligned. The combination of these two guarantee
that the data is always at 8 byte alignment.

Tested-by: Frederic Weisbecker <fweisbec@gmail.com>
           (on sparc64)
Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-18 23:11:35 -04:00
Linus Torvalds
f82c37e7bb Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (35 commits)
  perf: Fix unexported generic perf_arch_fetch_caller_regs
  perf record: Don't try to find buildids in a zero sized file
  perf: export perf_trace_regs and perf_arch_fetch_caller_regs
  perf, x86: Fix hw_perf_enable() event assignment
  perf, ppc: Fix compile error due to new cpu notifiers
  perf: Make the install relative to DESTDIR if specified
  kprobes: Calculate the index correctly when freeing the out-of-line execution slot
  perf tools: Fix sparse CPU numbering related bugs
  perf_event: Fix oops triggered by cpu offline/online
  perf: Drop the obsolete profile naming for trace events
  perf: Take a hot regs snapshot for trace events
  perf: Introduce new perf_fetch_caller_regs() for hot regs snapshot
  perf/x86-64: Use frame pointer to walk on irq and process stacks
  lockdep: Move lock events under lockdep recursion protection
  perf report: Print the map table just after samples for which no map was found
  perf report: Add multiple event support
  perf session: Change perf_session post processing functions to take histogram tree
  perf session: Add storage for seperating event types in report
  perf session: Change add_hist_entry to take the tree root instead of session
  perf record: Add ID and to recorded event data when recording multiple events
  ...
2010-03-18 16:52:46 -07:00
Frederic Weisbecker
dcd5c1662d perf: Fix unexported generic perf_arch_fetch_caller_regs
perf_arch_fetch_caller_regs() is exported for the overriden x86
version, but not for the generic weak version.

As a general rule, weak functions should not have their symbol
exported in the same file they are defined.

So let's export it on trace_event_perf.c as it is used by trace
events only.

This fixes:

	ERROR: ".perf_arch_fetch_caller_regs" [fs/xfs/xfs.ko] undefined!
	ERROR: ".perf_arch_fetch_caller_regs" [arch/powerpc/platforms/cell/spufs/spufs.ko] undefined!

-v2: And also only build it if trace events are enabled.
-v3: Fix changelog mistake

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1268697902-9518-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-17 12:26:49 +01:00
Linus Torvalds
4e3eaddd14 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  locking: Make sparse work with inline spinlocks and rwlocks
  x86/mce: Fix RCU lockdep splats
  rcu: Increase RCU CPU stall timeouts if PROVE_RCU
  ftrace: Replace read_barrier_depends() with rcu_dereference_raw()
  rcu: Suppress RCU lockdep warnings during early boot
  rcu, ftrace: Fix RCU lockdep splat in ftrace_perf_buf_prepare()
  rcu: Suppress __mpol_dup() false positive from RCU lockdep
  rcu: Make rcu_read_lock_sched_held() handle !PREEMPT
  rcu: Add control variables to lockdep_rcu_dereference() diagnostics
  rcu, cgroup: Relax the check in task_subsys_state() as early boot is now handled by lockdep-RCU
  rcu: Use wrapper function instead of exporting tasklist_lock
  sched, rcu: Fix rcu_dereference() for RCU-lockdep
  rcu: Make task_subsys_state() RCU-lockdep checks handle boot-time use
  rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU
  x86/gart: Unexport gart_iommu_aperture

Fix trivial conflicts in kernel/trace/ftrace.c
2010-03-13 14:43:01 -08:00
Linus Torvalds
8655e7e3dd Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing: Do not record user stack trace from NMI context
  tracing: Disable buffer switching when starting or stopping trace
  tracing: Use same local variable when resetting the ring buffer
  function-graph: Init curr_ret_stack with ret_stack
  ring-buffer: Move disabled check into preempt disable section
  function-graph: Add tracing_thresh support to function_graph tracer
  tracing: Update the comm field in the right variable in update_max_tr
  function-graph: Use comment notation for func names of dangling '}'
  function-graph: Fix unused reference to ftrace_set_func()
  tracing: Fix warning in s_next of trace file ops
  tracing: Include irqflags headers from trace clock
2010-03-13 14:40:50 -08:00
Steven Rostedt
b6345879cc tracing: Do not record user stack trace from NMI context
A bug was found with Li Zefan's ftrace_stress_test that caused applications
to segfault during the test.

Placing a tracing_off() in the segfault code, and examining several
traces, I found that the following was always the case. The lock tracer
was enabled (lockdep being required) and userstack was enabled. Testing
this out, I just enabled the two, but that was not good enough. I needed
to run something else that could trigger it. Running a load like hackbench
did not work, but executing a new program would. The following would
trigger the segfault within seconds:

  # echo 1 > /debug/tracing/options/userstacktrace
  # echo 1 > /debug/tracing/events/lock/enable
  # while :; do ls > /dev/null ; done

Enabling the function graph tracer and looking at what was happening
I finally noticed that all cashes happened just after an NMI.

 1)               |    copy_user_handle_tail() {
 1)               |      bad_area_nosemaphore() {
 1)               |        __bad_area_nosemaphore() {
 1)               |          no_context() {
 1)               |            fixup_exception() {
 1)   0.319 us    |              search_exception_tables();
 1)   0.873 us    |            }
[...]
 1)   0.314 us    |  __rcu_read_unlock();
 1)   0.325 us    |    native_apic_mem_write();
 1)   0.943 us    |  }
 1)   0.304 us    |  rcu_nmi_exit();
[...]
 1)   0.479 us    |  find_vma();
 1)               |  bad_area() {
 1)               |    __bad_area() {

After capturing several traces of failures, all of them happened
after an NMI. Curious about this, I added a trace_printk() to the NMI
handler to read the regs->ip to see where the NMI happened. In which I
found out it was here:

ffffffff8135b660 <page_fault>:
ffffffff8135b660:       48 83 ec 78             sub    $0x78,%rsp
ffffffff8135b664:       e8 97 01 00 00          callq  ffffffff8135b800 <error_entry>

What was happening is that the NMI would happen at the place that a page
fault occurred. It would call rcu_read_lock() which was traced by
the lock events, and the user_stack_trace would run. This would trigger
a page fault inside the NMI. I do not see where the CR2 register is
saved or restored in NMI handling. This means that it would corrupt
the page fault handling that the NMI interrupted.

The reason the while loop of ls helped trigger the bug, was that
each execution of ls would cause lots of pages to be faulted in, and
increase the chances of the race happening.

The simple solution is to not allow user stack traces in NMI context.
After this patch, I ran the above "ls" test for a couple of hours
without any issues. Without this patch, the bug would trigger in less
than a minute.

Cc: stable@kernel.org
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-12 20:31:49 -05:00
Steven Rostedt
a2f8071428 tracing: Disable buffer switching when starting or stopping trace
When the trace iterator is read, tracing_start() and tracing_stop()
is called to stop tracing while the iterator is processing the trace
output.

These functions disable both the standard buffer and the max latency
buffer. But if the wakeup tracer is running, it can switch these
buffers between the two disables:

  buffer = global_trace.buffer;
  if (buffer)
      ring_buffer_record_disable(buffer);

      <<<--------- swap happens here

  buffer = max_tr.buffer;
  if (buffer)
      ring_buffer_record_disable(buffer);

What happens is that we disabled the same buffer twice. On tracing_start()
we can enable the same buffer twice. All ring_buffer_record_disable()
must be matched with a ring_buffer_record_enable() or the buffer
can be disable permanently, or enable prematurely, and cause a bug
where a reset happens while a trace is commiting.

This patch protects these two by taking the ftrace_max_lock to prevent
a switch from occurring.

Found with Li Zefan's ftrace_stress_test.

Cc: stable@kernel.org
Reported-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-12 20:30:21 -05:00
Steven Rostedt
283740c619 tracing: Use same local variable when resetting the ring buffer
In the ftrace code that resets the ring buffer it references the
buffer with a local variable, but then uses the tr->buffer as the
parameter to reset. If the wakeup tracer is running, which can
switch the tr->buffer with the max saved buffer, this can break
the requirement of disabling the buffer before the reset.

   buffer = tr->buffer;
   ring_buffer_record_disable(buffer);
   synchronize_sched();
   __tracing_reset(tr->buffer, cpu);

If the tr->buffer is swapped, then the reset is not happening to the
buffer that was disabled. This will cause the ring buffer to fail.

Found with Li Zefan's ftrace_stress_test.

Cc: stable@kernel.org
Reported-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-12 20:29:20 -05:00
Steven Rostedt
ea14eb7140 function-graph: Init curr_ret_stack with ret_stack
If the graph tracer is active, and a task is forked but the allocating of
the processes graph stack fails, it can cause crash later on.

This is due to the temporary stack being NULL, but the curr_ret_stack
variable is copied from the parent. If it is not -1, then in
ftrace_graph_probe_sched_switch() the following:

	for (index = next->curr_ret_stack; index >= 0; index--)
		next->ret_stack[index].calltime += timestamp;

Will cause a kernel OOPS.

Found with Li Zefan's ftrace_stress_test.

Cc: stable@kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-12 20:28:02 -05:00
Lai Jiangshan
52fbe9cde7 ring-buffer: Move disabled check into preempt disable section
The ring buffer resizing and resetting relies on a schedule RCU
action. The buffers are disabled, a synchronize_sched() is called
and then the resize or reset takes place.

But this only works if the disabling of the buffers are within the
preempt disabled section, otherwise a window exists that the buffers
can be written to while a reset or resize takes place.

Cc: stable@kernel.org
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B949E43.2010906@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-12 20:26:56 -05:00
Xiao Guangrong
639fe4b12f perf: export perf_trace_regs and perf_arch_fetch_caller_regs
Export perf_trace_regs and perf_arch_fetch_caller_regs since module will
use these.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
[ use EXPORT_PER_CPU_SYMBOL_GPL() ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4B989C1B.2090407@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 15:21:29 +01:00
Ingo Molnar
915a0b575f Merge branch 'tip/tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/urgent 2010-03-11 13:39:33 +01:00
Paul E. McKenney
3f379b03fb ftrace: Replace read_barrier_depends() with rcu_dereference_raw()
Replace the calls to read_barrier_depends() in
ftrace_list_func() with rcu_dereference_raw() to improve
readability.  The reason that we use rcu_dereference_raw() here
is that removed entries are never freed, instead they are simply
leaked.  This is one of a very few cases where use of
rcu_dereference_raw() is the long-term right answer.  And I
don't yet know of any others.  ;-)

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1267830207-9474-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 13:38:01 +01:00
Frederic Weisbecker
97d5a22005 perf: Drop the obsolete profile naming for trace events
Drop the obsolete "profile" naming used by perf for trace events.
Perf can now do more than simple events counting, so generalize
the API naming.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
2010-03-10 14:47:18 +01:00
Frederic Weisbecker
c530665c31 perf: Take a hot regs snapshot for trace events
We are taking a wrong regs snapshot when a trace event triggers.
Either we use get_irq_regs(), which gives us the interrupted
registers if we are in an interrupt, or we use task_pt_regs()
which gives us the state before we entered the kernel, assuming
we are lucky enough to be no kernel thread, in which case
task_pt_regs() returns the initial set of regs when the kernel
thread was started.

What we want is different. We need a hot snapshot of the regs,
so that we can get the instruction pointer to record in the
sample, the frame pointer for the callchain, and some other
things.

Let's use the new perf_fetch_caller_regs() for that.

Comparison with perf record -e lock: -R -a -f -g
Before:

        perf  [kernel]                   [k] __do_softirq
               |
               --- __do_softirq
                  |
                  |--55.16%-- __open
                  |
                   --44.84%-- __write_nocancel

After:

            perf  [kernel]           [k] perf_tp_event
               |
               --- perf_tp_event
                  |
                  |--41.07%-- lock_acquire
                  |          |
                  |          |--39.36%-- _raw_spin_lock
                  |          |          |
                  |          |          |--7.81%-- hrtimer_interrupt
                  |          |          |          smp_apic_timer_interrupt
                  |          |          |          apic_timer_interrupt

The old case was producing unreliable callchains. Now having
right frame and instruction pointers, we have the trace we
want.

Also syscalls and kprobe events already have the right regs,
let's use them instead of wasting a retrieval.

v2: Follow the rename perf_save_regs() -> perf_fetch_caller_regs()

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Archs <linux-arch@vger.kernel.org>
2010-03-10 14:40:38 +01:00
Jiri Kosina
318ae2edc3 Merge branch 'for-next' into for-linus
Conflicts:
	Documentation/filesystems/proc.txt
	arch/arm/mach-u300/include/mach/debug-macro.S
	drivers/net/qlge/qlge_ethtool.c
	drivers/net/qlge/qlge_main.c
	drivers/net/typhoon.c
2010-03-08 16:55:37 +01:00
Tim Bird
0e95017355 function-graph: Add tracing_thresh support to function_graph tracer
Add support for tracing_thresh to the function_graph tracer.  This
version of this feature isolates the checks into new entry and
return functions, to avoid adding more conditional code into the
main function_graph paths.

When the tracing_thresh is set and the function graph tracer is
enabled, only the functions that took longer than the time in
microseconds that was set in tracing_thresh are recorded. To do this
efficiently, only the function exits are recorded:

 [tracing]# echo 100 > tracing_thresh
 [tracing]# echo function_graph > current_tracer
 [tracing]# cat trace
 # tracer: function_graph
 #
 # CPU  DURATION                  FUNCTION CALLS
 # |     |   |                     |   |   |   |
  1) ! 119.214 us  |  } /* smp_apic_timer_interrupt */
  1)   <========== |
  0) ! 101.527 us  |              } /* __rcu_process_callbacks */
  0) ! 126.461 us  |            } /* rcu_process_callbacks */
  0) ! 145.111 us  |          } /* __do_softirq */
  0) ! 149.667 us  |        } /* do_softirq */
  0) ! 168.817 us  |      } /* irq_exit */
  0) ! 248.254 us  |    } /* smp_apic_timer_interrupt */

Also, add support for specifying tracing_thresh on the kernel
command line.  When used like so: "tracing_thresh=200 ftrace=function_graph"
this can be used to analyse system startup.  It is important to disable
tracing soon after boot, in order to avoid losing the trace data.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Tim Bird <tim.bird@am.sony.com>
LKML-Reference: <4B87098B.4040308@am.sony.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-05 21:20:57 -05:00
Arnaldo Carvalho de Melo
1acaa1b2d9 tracing: Update the comm field in the right variable in update_max_tr
The latency output showed:

 #    | task: -3 (uid:0 nice:0 policy:1 rt_prio:99)

The comm is missing in the "task:" and it looks like a minus 3 is
the output. The correct display should be:

 #    | task: migration/0-3 (uid:0 nice:0 policy:1 rt_prio:99)

The problem is that the comm is being stored in the wrong data
structure. The max_tr.data[cpu] is what stores the comm, not the
tr->data[cpu].

Before this patch the max_tr.data[cpu]->comm was zeroed and the /debug/trace
ended up showing just the '-' sign followed by the pid.

Also remove a needless initialization of max_data.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1267824230-23861-1-git-send-email-acme@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-05 21:12:08 -05:00
Steven Rostedt
a094fe04c7 function-graph: Use comment notation for func names of dangling '}'
When a '}' does not have a matching function start, the name is printed
within parenthesis. But this makes it confusing between ending '}'
and function starts. This patch makes the function name appear in C comment
notation.

Old view:
 3)   1.281 us    |            } (might_fault)
 3)   3.620 us    |          } (filldir)
 3)   5.251 us    |        } (call_filldir)
 3)               |        call_filldir() {
 3)               |          filldir() {

New view:
 3)   1.281 us    |            } /* might_fault */
 3)   3.620 us    |          } /* filldir */
 3)   5.251 us    |        } /* call_filldir */
 3)               |        call_filldir() {
 3)               |          filldir() {

Requested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-05 21:11:13 -05:00
Steven Rostedt
801c29fd1f function-graph: Fix unused reference to ftrace_set_func()
The declaration of ftrace_set_func() is at the start of the ftrace.c file
and wrapped with a #ifdef CONFIG_FUNCTION_GRAPH condition. If function
graph tracing is enabled but CONFIG_DYNAMIC_FTRACE is not, a warning
about that function being declared static and unused is given.

This really should have been placed within the CONFIG_FUNCTION_GRAPH
condition that uses ftrace_set_func().

Moving the declaration down fixes the warning and makes the code cleaner.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-05 21:00:30 -05:00
Paul E. McKenney
8d53dd546f rcu, ftrace: Fix RCU lockdep splat in ftrace_perf_buf_prepare()
Change the pair of rcu_dereference() calls in
ftrace_perf_buf_prepare() to rcu_dereference_sched().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1267667418-32233-3-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-04 12:07:35 +01:00
Ingo Molnar
e02c4fd314 Merge branch 'tip/tracing/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/urgent 2010-03-04 11:51:29 +01:00
Linus Torvalds
0a135ba14d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: add __percpu sparse annotations to what's left
  percpu: add __percpu sparse annotations to fs
  percpu: add __percpu sparse annotations to core kernel subsystems
  local_t: Remove leftover local.h
  this_cpu: Remove pageset_notifier
  this_cpu: Page allocator conversion
  percpu, x86: Generic inc / dec percpu instructions
  local_t: Move local.h include to ringbuffer.c and ring_buffer_benchmark.c
  module: Use this_cpu_xx to dynamically allocate counters
  local_t: Remove cpu_local_xx macros
  percpu: refactor the code in pcpu_[de]populate_chunk()
  percpu: remove compile warnings caused by __verify_pcpu_ptr()
  percpu: make accessors check for percpu pointer in sparse
  percpu: add __percpu for sparse.
  percpu: make access macros universal
  percpu: remove per_cpu__ prefix.
2010-03-03 07:34:18 -08:00
Lai Jiangshan
ac91d85456 tracing: Fix warning in s_next of trace file ops
This warning in s_next() can be triggered by lseek():
 [<c018b3f7>] ? s_next+0x77/0x80
 [<c013e3c1>] warn_slowpath_common+0x81/0xa0
 [<c018b3f7>] ? s_next+0x77/0x80
 [<c013e3fa>] warn_slowpath_null+0x1a/0x20
 [<c018b3f7>] s_next+0x77/0x80
 [<c01efa77>] traverse+0x117/0x200
 [<c01eff13>] seq_lseek+0xa3/0x120
 [<c01efe70>] ? seq_lseek+0x0/0x120
 [<c01d7081>] vfs_llseek+0x41/0x50
 [<c01d8116>] sys_llseek+0x66/0xa0
 [<c0102bd0>] sysenter_do_call+0x12/0x26

The iterator "leftover" variable is zeroed in the opening of the trace
file. But lseek can call s_start() which will call s_next() without
reseting the "leftover" variable back to zero, which might trigger
the WARN_ON_ONCE(iter->leftover) that is in s_next().

Cc: stable@kernel.org
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B8CE06A.9090207@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-02 21:11:47 -05:00
Linus Torvalds
b1bf936840 Merge branch 'for-2.6.34' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.34' of git://git.kernel.dk/linux-2.6-block: (38 commits)
  block: don't access jiffies when initialising io_context
  cfq: remove 8 bytes of padding from cfq_rb_root on 64 bit builds
  block: fix for "Consolidate phys_segment and hw_segment limits"
  cfq-iosched: quantum check tweak
  blktrace: perform cleanup after setup error
  blkdev: fix merge_bvec_fn return value checks
  cfq-iosched: requests "in flight" vs "in driver" clarification
  cciss: Fix problem with scatter gather elements in the scsi half of the driver
  cciss: eliminate unnecessary pointer use in cciss scsi code
  cciss: do not use void pointer for scsi hba data
  cciss: factor out scatter gather chain block mapping code
  cciss: fix scatter gather chain block dma direction kludge
  cciss: simplify scatter gather code
  cciss: factor out scatter gather chain block allocation and freeing
  cciss: detect bad alignment of scsi commands at build time
  cciss: clarify command list padding calculation
  cfq-iosched: rethink seeky detection for SSDs
  cfq-iosched: rework seeky detection
  block: remove padding from io_context on 64bit builds
  block: Consolidate phys_segment and hw_segment limits
  ...
2010-03-01 09:00:29 -08:00
Dmitry Monakhov
9a8c28c831 blktrace: perform cleanup after setup error
Currently even if BLKTRACESETUP ioctl has failed user must call
BLKTRACETEARDOWN to be shure what all staff was cleaned, which
is contr-intuitive.
Let's setup ioctl make necessery cleanup by it self.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-02-28 19:47:19 +01:00
Frederic Weisbecker
ae1f30384b tracing: Include irqflags headers from trace clock
trace_clock.c includes spinlock.h, which ends up including
asm/system.h, which in turn includes linux/irqflags.h in x86.

So the definition of raw_local_irq_save is luckily covered there,
but this is not the case in parisc:

   tip/kernel/trace/trace_clock.c:86: error: implicit declaration of function 'raw_local_irq_save'
   tip/kernel/trace/trace_clock.c:112: error: implicit declaration of function 'raw_local_irq_restore'

We need to include linux/irqflags.h directly from trace_clock.c
to avoid such build error.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-28 19:45:01 +01:00
Linus Torvalds
6556a67435 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (172 commits)
  perf_event, amd: Fix spinlock initialization
  perf_event: Fix preempt warning in perf_clock()
  perf tools: Flush maps on COMM events
  perf_events, x86: Split PMU definitions into separate files
  perf annotate: Handle samples not at objdump output addr boundaries
  perf_events, x86: Remove superflous MSR writes
  perf_events: Simplify code by removing cpu argument to hw_perf_group_sched_in()
  perf_events, x86: AMD event scheduling
  perf_events: Add new start/stop PMU callbacks
  perf_events: Report the MMAP pgoff value in bytes
  perf annotate: Defer allocating sym_priv->hist array
  perf symbols: Improve debugging information about symtab origins
  perf top: Use a macro instead of a constant variable
  perf symbols: Check the right return variable
  perf/scripts: Tag syscall_name helper as not yet available
  perf/scripts: Add perf-trace-python Documentation
  perf/scripts: Remove unnecessary PyTuple resizes
  perf/scripts: Add syscall tracing scripts
  perf/scripts: Add Python scripting engine
  perf/scripts: Remove check-perf-trace from listed scripts
  ...

Fix trivial conflict in tools/perf/util/probe-event.c
2010-02-28 10:20:25 -08:00
Ingo Molnar
480917427b Merge branch 'tip/tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/core 2010-02-27 10:41:16 +01:00
Ingo Molnar
6fb83029db Merge branch 'tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into tracing/core 2010-02-27 10:06:10 +01:00
Steven Rostedt
f1c7f517a5 ftrace: Add function names to dangling } in function graph tracer
The function graph tracer is currently the most invasive tracer
in the ftrace family. It can easily overflow the buffer even with
10megs per CPU. This means that events can often be lost.

On start up, or after events are lost, if the function return is
recorded but the function enter was lost, all we get to see is the
exiting '}'.

Here is how a typical trace output starts:

 [tracing] cat trace
 # tracer: function_graph
 #
 # CPU  DURATION                  FUNCTION CALLS
 # |     |   |                     |   |   |   |
  0) + 91.897 us   |                  }
  0) ! 567.961 us  |                }
  0)   <========== |
  0) ! 579.083 us  |                _raw_spin_lock_irqsave();
  0)   4.694 us    |                _raw_spin_unlock_irqrestore();
  0) ! 594.862 us  |              }
  0) ! 603.361 us  |            }
  0) ! 613.574 us  |          }
  0) ! 623.554 us  |        }
  0)   3.653 us    |        fget_light();
  0)               |        sock_poll() {

There are a series of '}' with no matching "func() {". There's no information
to what functions these ending brackets belong to.

This patch adds a stack on the per cpu structure used in outputting
the function graph tracer to keep track of what function was outputted.
Then on a function exit event, it checks the depth to see if the
function exit has a matching entry event. If it does, then it only
prints the '}', otherwise it adds the function name after the '}'.

This allows function exit events to show what function they belong to
at trace output startup, when the entry was lost due to ring buffer
overflow, or even after a new task is scheduled in.

Here is what the above trace will look like after this patch:

 [tracing] cat trace
 # tracer: function_graph
 #
 # CPU  DURATION                  FUNCTION CALLS
 # |     |   |                     |   |   |   |
  0) + 91.897 us   |                  } (irq_exit)
  0) ! 567.961 us  |                } (smp_apic_timer_interrupt)
  0)   <========== |
  0) ! 579.083 us  |                _raw_spin_lock_irqsave();
  0)   4.694 us    |                _raw_spin_unlock_irqrestore();
  0) ! 594.862 us  |              } (add_wait_queue)
  0) ! 603.361 us  |            } (__pollwait)
  0) ! 613.574 us  |          } (tcp_poll)
  0) ! 623.554 us  |        } (sock_poll)
  0)   3.653 us    |        fget_light();
  0)               |        sock_poll() {

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-26 19:25:53 -05:00
Ingo Molnar
281b3714e9 Merge branch 'tip/tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/core 2010-02-26 09:20:17 +01:00
Ingo Molnar
64b9fb5704 Merge commit 'v2.6.33' into tracing/core
Conflicts:
	scripts/recordmcount.pl

Merge reason: Merge up to v2.6.33.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-26 09:18:32 +01:00
Wenji Huang
7b60997f73 tracing: Simplify memory recycle of trace_define_field
Discard freeing field->type since it is not necessary.

Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
LKML-Reference: <1266997226-6833-5-git-send-email-wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25 10:42:55 -05:00
Wenji Huang
c85f3a91f8 tracing: Remove unnecessary variable in print_graph_return
The "cpu" variable is declared at the start of the function and
also within a branch, with the exact same initialization.

Remove the local variable of the same name in the branch.

Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
LKML-Reference: <1266997226-6833-3-git-send-email-wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25 10:41:24 -05:00
Wenji Huang
a5efd92511 tracing: Fix typo of info text in trace_kprobe.c
Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
LKML-Reference: <1266997226-6833-2-git-send-email-wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25 10:36:29 -05:00
Wenji Huang
6574658b3b tracing: Fix typo in prof_sysexit_enable()
Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
LKML-Reference: <1266997226-6833-1-git-send-email-wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25 10:35:55 -05:00
Li Zefan
1ab83a8941 tracing: Remove CONFIG_TRACE_POWER from kernel config
The power tracer has been converted to power trace events.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B84D50E.4070806@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25 10:31:45 -05:00
Jeff Mahoney
86c38a31aa tracing: Fix ftrace_event_call alignment for use with gcc 4.5
GCC 4.5 introduces behavior that forces the alignment of structures to
 use the largest possible value. The default value is 32 bytes, so if
 some structures are defined with a 4-byte alignment and others aren't
 declared with an alignment constraint at all - it will align at 32-bytes.

 For things like the ftrace events, this results in a non-standard array.
 When initializing the ftrace subsystem, we traverse the _ftrace_events
 section and call the initialization callback for each event. When the
 structures are misaligned, we could be treating another part of the
 structure (or the zeroed out space between them) as a function pointer.

 This patch forces the alignment for all the ftrace_event_call structures
 to 4 bytes.

 Without this patch, the kernel fails to boot very early when built with
 gcc 4.5.

 It's trivial to check the alignment of the members of the array, so it
 might be worthwhile to add something to the build system to do that
 automatically. Unfortunately, that only covers this case. I've asked one
 of the gcc developers about adding a warning when this condition is seen.

Cc: stable@kernel.org
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
LKML-Reference: <4B85770B.6010901@suse.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25 09:38:11 -05:00
Heiko Carstens
f850c30c8b tracing/kprobes: Make Kconfig dependencies generic
KPROBES_EVENT actually depends on the regs and stack access API
(b1cf540f) and not on x86.
So introduce a new config option which architectures can select if
they have the API implemented and switch x86.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
LKML-Reference: <20100210162517.GB6933@osiris.boeblingen.de.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-02-17 13:13:08 +01:00
Mike Frysinger
e7b8e675d9 tracing: Unify arch_syscall_addr() implementations
Most implementations of arch_syscall_addr() are the same, so create a
default version in common code and move the one piece that differs (the
syscall table) to asm/syscall.h.  New arch ports don't have to waste
time copying & pasting this simple function.

The s390/sparc versions need to be different, so document why.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1264498803-17278-1-git-send-email-vapier@gentoo.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-02-17 13:07:21 +01:00
Heiko Carstens
a9bb18f36c tracing/kprobes: Fix probe parsing
Trying to add a probe like:

  echo p:myprobe 0x10000 > /sys/kernel/debug/tracing/kprobe_events

will fail since the wrong pointer is passed to strict_strtoul
when trying to convert the address to an unsigned long.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100210162346.GA6933@osiris.boeblingen.de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-14 09:43:58 +01:00
Li Zefan
c7c6b1fe9f ftrace: Allow to remove a single function from function graph filter
I don't see why we can only clear all functions from the filter.

After patching:

  # echo sys_open > set_graph_function
  # echo sys_close >> set_graph_function
  # cat set_graph_function
  sys_open
  sys_close
  # echo '!sys_close' >> set_graph_function
  # cat set_graph_function
  sys_open

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B726388.2000408@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-11 14:32:38 -05:00
Steven Rostedt
ede55c9d78 tracing: Add correct/incorrect to sort keys for branch annotation output
The branch annotation is a bit difficult to see the worst offenders
because it only sorts by percentage:

 correct incorrect  %        Function                  File              Line
 ------- ---------  -        --------                  ----              ----
       0      163 100 qdisc_restart                  sch_generic.c        179
       0      163 100 pfifo_fast_dequeue             sch_generic.c        447
       0        4 100 pskb_trim_rcsum                skbuff.h             1689
       0        4 100 llc_rcv                        llc_input.c          170
       0       18 100 psmouse_interrupt              psmouse-base.c       304
       0        3 100 atkbd_interrupt                atkbd.c              389
       0        5 100 usb_alloc_dev                  usb.c                437
       0       11 100 vsscanf                        vsprintf.c           1897
       0        2 100 IS_ERR                         err.h                34
       0       23 100 __rmqueue_fallback             page_alloc.c         865
       0        4 100 probe_wakeup_sched_switch      trace_sched_wakeup.c 142
       0        3 100 move_masked_irq                migration.c          11

Adding the incorrect and correct values as sort keys makes this file a
bit more informative:

 correct incorrect  %        Function                  File              Line
 ------- ---------  -        --------                  ----              ----
       0   366541 100 audit_syscall_entry            auditsc.c            1637
       0   366538 100 audit_syscall_exit             auditsc.c            1685
       0   115839 100 sched_info_switch              sched_stats.h        269
       0    74567 100 sched_info_queued              sched_stats.h        222
       0    66578 100 sched_info_dequeued            sched_stats.h        177
       0    15113 100 trace_workqueue_insertion      workqueue.h          38
       0    15107 100 trace_workqueue_execution      workqueue.h          45
       0     3622 100 syscall_trace_leave            ptrace.c             1772
       0     2750 100 sched_move_task                sched.c              10100
       0     2750 100 sched_move_task                sched.c              10110
       0     1815 100 pre_schedule_rt                sched_rt.c           1462
       0      837 100 audit_alloc                    auditsc.c            879
       0      814 100 tcp_mss_split_point            tcp_output.c         1302

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-09 21:35:05 -05:00
Daniel Mack
1537a3638c tree-wide: fix 'lenght' typo in comments and code
Some misspelled occurences of 'octet' and some comments were also fixed
as I was on it.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Jiri Kosina <trivial@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-02-05 12:22:45 +01:00
Adam Buchbinder
c41b20e721 Fix misspellings of "truly" in comments.
Some comments misspell "truly"; this fixes them. No code changes.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-02-04 11:55:45 +01:00
Masami Hiramatsu
f24bb999d2 ftrace: Remove record freezing
Remove record freezing. Because kprobes never puts probe on
ftrace's mcount call anymore, it doesn't need ftrace to check
whether kprobes on it.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: przemyslaw@pawelczyk.it
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100202214925.4694.73469.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-04 09:36:19 +01:00
Masami Hiramatsu
2cfa19780d ftrace/alternatives: Introducing *_text_reserved functions
Introducing *_text_reserved functions for checking the text
address range is partially reserved or not. This patch provides
checking routines for x86 smp alternatives and dynamic ftrace.
Since both functions modify fixed pieces of kernel text, they
should reserve and protect those from other dynamic text
modifier, like kprobes.

This will also be extended when introducing other subsystems
which modify fixed pieces of kernel text. Dynamic text modifiers
should avoid those.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: przemyslaw@pawelczyk.it
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: Jason Baron <jbaron@redhat.com>
LKML-Reference: <20100202214911.4694.16587.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-04 09:36:19 +01:00
Lai Jiangshan
4f48f8b7fd tracing: Fix circular dead lock in stack trace
When we cat <debugfs>/tracing/stack_trace, we may cause circular lock:
sys_read()
  t_start()
     arch_spin_lock(&max_stack_lock);

  t_show()
     seq_printf(), vsnprintf() .... /* they are all trace-able,
       when they are traced, max_stack_lock may be required again. */

The following script can trigger this circular dead lock very easy:
#!/bin/bash

echo 1 > /proc/sys/kernel/stack_tracer_enabled

mount -t debugfs xxx /mnt > /dev/null 2>&1

(
# make check_stack() zealous to require max_stack_lock
for ((; ;))
{
	echo 1 > /mnt/tracing/stack_max_size
}
) &

for ((; ;))
{
	cat /mnt/tracing/stack_trace > /dev/null
}

To fix this bug, we increase the percpu trace_active before
require the lock.

Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B67D4F9.9080905@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-02 10:20:18 -05:00
Tejun Heo
ab386128f2 Merge branch 'master' into percpu 2010-02-02 14:38:15 +09:00
Ingo Molnar
ae7f6711d6 Merge branch 'perf/urgent' into perf/core
Merge reason: We want to queue up a dependent patch. Also update to
              later -rc's.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-29 10:36:22 +01:00
Xiao Guangrong
1e12a4a7a3 tracing/kprobe: Cleanup unused return value of tracing functions
The return values of the kprobe's tracing functions are meaningless,
lets remove these.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <4B60E9A3.2040505@cn.fujitsu.com>
[fweisbec@gmail: whitespace fixes, drop useless void returns in end
of functions]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-01-29 02:14:40 +01:00
Xiao Guangrong
430ad5a600 perf: Factorize trace events raw sample buffer operations
Introduce ftrace_perf_buf_prepare() and ftrace_perf_buf_submit() to
gather the common code that operates on raw events sampling buffer.
This cleans up redundant code between regular trace events, syscall
events and kprobe events.

Changelog v1->v2:
- Rename function name as per Masami and Frederic's suggestion
- Add __kprobes for ftrace_perf_buf_prepare() and make
  ftrace_perf_buf_submit() inline as per Masami's suggestion
- Export ftrace_perf_buf_prepare since modules will use it

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <4B60E92D.9000808@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-01-29 02:02:57 +01:00
Lai Jiangshan
ea2c68a08f tracing: Simplify test for function_graph tracing start point
In the function graph tracer, a calling function is to be traced
only when it is enabled through the set_graph_function file,
or when it is nested in an enabled function.

Current code uses TSK_TRACE_FL_GRAPH to test whether it is nested
or not. Looking at the code, we can get this:
(trace->depth > 0) <==> (TSK_TRACE_FL_GRAPH is set)

trace->depth is more explicit to tell that it is nested.
So we use trace->depth directly and simplify the code.

No functionality is changed.
TSK_TRACE_FL_GRAPH is not removed yet, it is left for future usage.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4B4DB0B6.7040607@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-01-29 01:05:12 +01:00
Mike Frysinger
0368897034 tracing/documentation: Cover new frame pointer semantics
Update the graph tracer examples to cover the new frame pointer semantics
(in terms of passing it along).  Move the HAVE_FUNCTION_GRAPH_FP_TEST docs
out of the Kconfig, into the right place, and expand on the details.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
LKML-Reference: <1264165967-18938-1-git-send-email-vapier@gentoo.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-26 17:00:39 -05:00
Steven Rostedt
3c05d74827 ring-buffer: Check for end of page in iterator
If the iterator comes to an empty page for some reason, or if
the page is emptied by a consuming read. The iterator code currently
does not check if the iterator is pass the contents, and may
return a false entry.

This patch adds a check to the ring buffer iterator to test if the
current page has been completely read and sets the iterator to the
next page if necessary.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-26 16:14:08 -05:00
Steven Rostedt
492a74f421 ring-buffer: Check if ring buffer iterator has stale data
Usually reads of the ring buffer is performed by a single task.
There are two types of reads from the ring buffer.

One is a consuming read which will consume the entry that was read
and the next read will be the entry that follows.

The other is an iterator that will let the user read the contents of
the ring buffer without modifying it. When an iterator is allocated,
writes to the ring buffer are disabled to protect the iterator.

The problem exists when consuming reads happen while an iterator is
allocated. Specifically, the kind of read that swaps out an entire
page (used by splice) and replaces it with a new read. If the iterator
is on the page that is swapped out, then the next read may read
from this swapped out page and return garbage.

This patch adds a check when reading the iterator to make sure that
the iterator contents are still valid. If a consuming read has taken
place, the iterator is reset.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-26 16:09:30 -05:00
Steven Rostedt
74bf4076f2 tracing: Prevent kernel oops with corrupted buffer
If the contents of the ftrace ring buffer gets corrupted and the trace
file is read, it could create a kernel oops (usualy just killing the user
task thread). This is caused by the checking of the pid in the buffer.
If the pid is negative, it still references the cmdline cache array,
which could point to an invalid address.

The simple fix is to test for negative PIDs.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-25 15:11:53 -05:00
Masami Hiramatsu
231e36f4d2 tracing/kprobe: Update kprobe tracing self test for new syntax
Update kprobe tracing self test for new syntax (it supports
deleting individual probes, and drops $argN support)
and behavior change (new probes are disabled in default).

This selftest includes the following checks:

 - Adding function-entry probe and return probe with arguments.
 - Enabling these probes.
 - Deleting it individually.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100114051211.7814.29436.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-17 08:15:35 +01:00
Frederic Weisbecker
24a53652e3 tracing: Drop the tr check from the graph tracing path
Each time we save a function entry from the function graph
tracer, we check if the trace array is set, which is wasteful
because it is set anyway before we start the tracer. All we need
is to ensure we have good read and write orderings. When we set
the trace array, we just need to guarantee it to be visible
before starting tracing.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
LKML-Reference: <1263453795-7496-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-17 08:06:25 +01:00
Li Zefan
d1303dd1d6 tracing/filters: Add comment for match callbacks
We should be clear on 2 things:

- the length parameter of a match callback includes
  tailing '\0'.

- the string to be searched might not be NULL-terminated.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8770.7000608@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:14 -05:00
Li Zefan
16da27a8bc tracing/filters: Fix MATCH_FULL filter matching for PTR_STRING
MATCH_FULL matching for PTR_STRING is not working correctly:

  # echo 'func == vt' > events/bkl/lock_kernel/filter
  # echo 1 > events/bkl/lock_kernel/enable
  ...
  # cat trace
   Xorg-1484  [000]  1973.392586: lock_kernel: ... func=vt_ioctl()
    gpm-1402  [001]  1974.027740: lock_kernel: ... func=vt_ioctl()

We should pass to regex.match(..., len) the length (including '\0')
of the source string instead of the length of the pattern string.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8763.5070707@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:12 -05:00
Li Zefan
b2af211f28 tracing/filters: Fix MATCH_MIDDLE_ONLY filter matching
The @str might not be NULL-terminated if it's of type
DYN_STRING or STATIC_STRING, so we should use strnstr()
instead of strstr().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8753.2000102@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:11 -05:00
Li Zefan
a3291c14ec tracing/filters: Fix MATCH_END_ONLY filter matching
For '*foo' pattern, we should allow any string ending with
'foo', but event filtering incorrectly disallows strings
like bar_foo_foo:

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8735.6070604@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:07 -05:00
Li Zefan
285caad415 tracing/filters: Fix MATCH_FRONT_ONLY filter matching
MATCH_FRONT_ONLY actually is a full matching:

  # ./perf record -R -f -a -e lock:lock_acquire \
	--filter 'name ~rcu_*' sleep 1
  # ./perf trace
  (no output)

We should pass the length of the pattern string to strncmp().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8721.5090301@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:05 -05:00
Li Zefan
751e9983ee ftrace: Fix MATCH_END_ONLY function filter
For '*foo' pattern, we should allow any string ending with
'foo', but ftrace filter incorrectly disallows strings
like bar_foo_foo:

  # echo '*io' > set_ftrace_filter
  # cat set_ftrace_filter | grep 'req_bio_endio'
  # cat available_filter_functions | grep 'req_bio_endio'
  req_bio_endio

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E870E.6060607@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:03 -05:00
Masami Hiramatsu
14640106f2 tracing/kprobe: Drop function argument access syntax
Drop function argument access syntax, because the function
arguments depend on not only architecture but also
compile-options and function API. And now, we have perf-probe
for finding register/memory assigned to each argument.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Neuling <mikey@neuling.org>
Cc: linuxppc-dev@ozlabs.org
LKML-Reference: <20100105224648.19431.52309.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-13 10:09:12 +01:00
Ingo Molnar
61405fea92 Merge branch 'perf/urgent' into perf/core
Merge reason: queue up dependent patch, update to -rc4

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-13 10:08:50 +01:00
Steven Rostedt
0e1ff5d72a ring-buffer: Add rb_list_head() wrapper around new reader page next field
If the very unlikely case happens where the writer moves the head by one
between where the head page is read and where the new reader page
is assigned _and_ the writer then writes and wraps the entire ring buffer
so that the head page is back to what was originally read as the head page,
the page to be swapped will have a corrupted next pointer.

Simple solution is to wrap the assignment of the next pointer with a
rb_list_head().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 20:40:44 -05:00
David Sharp
5ded3dc6a3 ring-buffer: Wrap a list.next reference with rb_list_head()
This reference at the end of rb_get_reader_page() was causing off-by-one
writes to the prev pointer of the page after the reader page when that
page is the head page, and therefore the reader page has the RB_PAGE_HEAD
flag in its list.next pointer. This eventually results in a GPF in a
subsequent call to rb_set_head_page() (usually from rb_get_reader_page())
when that prev pointer is dereferenced. The dereferenced register would
characteristically have an address that appears shifted left by one byte
(eg, ffxxxxxxxxxxxxyy instead of ffffxxxxxxxxxxxx) due to being written at
an address one byte too high.

Signed-off-by: David Sharp <dhsharp@google.com>
LKML-Reference: <1262826727-9090-1-git-send-email-dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 20:38:25 -05:00
Steven Rostedt
d931369b74 tracing: Add stack dump to trace_printk if stacktrace option is set
If the ftrace stacktrace option is set, then add the stack dumps to
trace_printk.

Requested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 18:09:57 -05:00
Lai Jiangshan
7e53bd42d1 tracing: Consolidate protection of reader access to the ring buffer
At the beginning, access to the ring buffer was fully serialized
by trace_types_lock. Patch d7350c3f45 gives more freedom to readers,
and patch b04cc6b1f6 adds code to protect trace_pipe and cpu#/trace_pipe.

But actually it is not enough, ring buffer readers are not always
read-only, they may consume data.

This patch makes accesses to trace, trace_pipe, trace_pipe_raw
cpu#/trace, cpu#/trace_pipe and cpu#/trace_pipe_raw serialized.
And removes tracing_reader_cpumask which is used to protect trace_pipe.

Details:

Ring buffer serializes readers, but it is low level protection.
The validity of the events (which returns by ring_buffer_peek() ..etc)
are not protected by ring buffer.

The content of events may become garbage if we allow another process to consume
these events concurrently:
  A) the page of the consumed events may become a normal page
     (not reader page) in ring buffer, and this page will be rewritten
     by the events producer.
  B) The page of the consumed events may become a page for splice_read,
     and this page will be returned to system.

This patch adds trace_access_lock() and trace_access_unlock() primitives.

These primitives allow multi process access to different cpu ring buffers
concurrently.

These primitives don't distinguish read-only and read-consume access.
Multi read-only access is also serialized.

And we don't use these primitives when we open files,
we only use them when we read files.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B447D52.1050602@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 12:51:34 -05:00
Lai Jiangshan
0fa0edaf32 tracing: Remove show_format and related macros from TRACE_EVENT
The previous patches added the use of print_fmt string and changes
the trace_define_field() function to also create the fields and
format output for the event format files.

   text	   data	    bss	    dec	    hex	filename
5857201	1355780	9336808	16549789	 fc879d	vmlinux
5884589	1351684	9337896	16574169	 fce6d9	vmlinux-orig

The above shows the size of the vmlinux after this patch set
compared to the vmlinux-orig which is before the patch set.

This saves us 27k on text, 1k on bss and adds just 4k of data.

The total savings of 24k in size.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D4D.40604@cn.fujitsu.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 12:08:46 -05:00
Lai Jiangshan
5a65e95622 tracing: Use defined fields and print_fmt to print formats
The calls ftrace_format_##call() and ftrace_define_fields_##call()
are almost duplicate in functionality. With the addition of the
print_fmt in previous patches, these two functions can be merged
into one.

The trace_define_field() defines the fields and links them into
the struct ftrace_event_call. The previous patches introduced
the print_fmt field and this can now be used with the trace_define_field()
to create the event format file fields and print_fmt field.

The struct ftrace_event_call->fields are used to print the fields
The struct ftrace_event_call->print_fmt is used to print
the "print fmt: XXXXXXXXXXX" line.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D49.5000006@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 12:08:20 -05:00
Steven Rostedt
c7ef3a9004 tracing: Have syscall tracing call its own init function
In the clean up of having all events call one specific function,
the syscall event init was changed to call this helper function.

With the new print_fmt updates, the syscalls need to do special
initializations. This patch converts the syscall events to call
its own init function again.

Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 12:02:32 -05:00
Lai Jiangshan
a342a0280b tracing/kprobes: Init print_fmt for kprobe events
This is part of a patch set that removes the show_format method
in the ftrace event macros.

Add the print_fmt initialization to the kprobe events.
The print_fmt is still not used, but will be in the follow up
patches.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D45.3080100@cn.fujitsu.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 12:01:35 -05:00