Commit Graph

9372 Commits

Author SHA1 Message Date
Ian Campbell
eed63519e3 x86: Do not free zero sized per cpu areas
This avoids an infinite loop in free_early_partial().

Add a warning to free_early_partial() to catch future problems.

-v5: put back start > end back into WARN_ONCE()
-v6: use one line for warning, suggested by Linus
-v7: more tests
-v8: remove the function name as suggested by Johannes
     WARN_ONCE() will print out that function name.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Joel Becker <joel.becker@oracle.com>
Tested-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1269830604-26214-4-git-send-email-yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-29 18:55:40 +02:00
Linus Torvalds
b72c40949b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  x86/PCI: truncate _CRS windows with _LEN > _MAX - _MIN + 1
  x86/PCI: for host bridge address space collisions, show conflicting resource
  frv/PCI: remove redundant warnings
  x86/PCI: remove redundant warnings
  PCI: don't say we claimed a resource if we failed
  PCI quirk: Disable MSI on VIA K8T890 systems
  PCI quirk: RS780/RS880: work around missing MSI initialization
  PCI quirk: only apply CX700 PCI bus parking quirk if external VT6212L is present
  PCI: complain about devices that seem to be broken
  PCI: print resources consistently with %pR
  PCI: make disabled window printk style match the enabled ones
  PCI: break out primary/secondary/subordinate for readability
  PCI: for address space collisions, show conflicting resource
  resources: add interfaces that return conflict information
  PCI: cleanup error return for pcix get and set mmrbc functions
  PCI: fix access of PCI_X_CMD by pcix get and set mmrbc functions
  PCI: kill off pci_register_set_vga_state() symbol export.
  PCI: fix return value from pcix_get_max_mmrbc()
2010-03-26 16:34:29 -07:00
Linus Torvalds
054319b5e2 Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  time: Fix accumulation bug triggered by long delay.
  posix-cpu-timers: Reset expire cache when no timer is running
  timer stats: Fix del_timer_sync() and try_to_del_timer_sync()
  clockevents: Sanitize min_delta_ns adjustment and prevent overflows
2010-03-26 15:10:38 -07:00
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
Linus Torvalds
3cacf42462 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Use proper type in sched_getaffinity()
  kernel/sched.c: Suppress unused var warning
  sched: sched_getaffinity(): Allow less than NR_CPUS length
2010-03-26 15:09:59 -07:00
Linus Torvalds
309d1dcb5b Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq: Move two IRQ functions from .init.text to .text
  genirq: Protect access to irq_desc->action in can_request_irq()
  genirq: Prevent oneshot irq thread race
2010-03-26 15:09:06 -07:00
Linus Torvalds
8128f55a0b 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:
  x86: Remove excessive early_res debug output
  softlockup: Stop spurious softlockup messages due to overflow
  rcu: Fix local_irq_disable() CONFIG_PROVE_RCU=y false positives
  rcu: Fix tracepoints & lockdep false positive
  rcu: Make rcu_read_lock_bh_held() allow for disabled BH
2010-03-26 15:08:31 -07:00
Miao Xie
53feb29767 cpuset: alloc nodemask_t on the heap rather than the stack
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24 16:31:21 -07:00
Miao Xie
5ab116c934 cpuset: fix the problem that cpuset_mem_spread_node() returns an offline node
cpuset_mem_spread_node() returns an offline node, and causes an oops.

This patch fixes it by initializing task->mems_allowed to
node_states[N_HIGH_MEMORY], and updating task->mems_allowed when doing
memory hotplug.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Reported-by: Nick Piggin <npiggin@suse.de>
Tested-by: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24 16:31:21 -07:00
Li Zefan
9d34706f42 cgroups: remove duplicate include
commit e6a1105b ("cgroups: subsystem module loading interface") and commit
c50cc752 ("sched, cgroups: Fix module export") result in duplicate
including of module.h

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24 16:31:19 -07:00
Henrik Kretzschmar
860652bfb8 genirq: Move two IRQ functions from .init.text to .text
Both functions should not be marked as __init, since they be called
from modules after the init section is freed.

Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jkosina@suse.cz>
LKML-Reference: <1269431961-5731-1-git-send-email-henne@nachtwindheim.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-03-24 14:38:23 +01:00
Thomas Gleixner
cc8c3b7843 genirq: Protect access to irq_desc->action in can_request_irq()
can_request_irq() accesses and dereferences irq_desc->action w/o
holding irq_desc->lock. So action can be freed on another CPU before
it's dereferenced. Unlikely, but ...

Protect it with desc->lock.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-03-24 14:38:23 +01:00
Bjorn Helgaas
66f1207bce resources: add interfaces that return conflict information
request_resource() and insert_resource() only return success or failure,
which no information about what existing resource conflicted with the
proposed new reservation.  This patch adds request_resource_conflict()
and insert_resource_conflict(), which return the conflicting resource.

Callers may use this for better error messages or to adjust the new
resource and retry the request.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-03-23 13:33:50 -07:00
John Stultz
830ec0458c time: Fix accumulation bug triggered by long delay.
The logarithmic accumulation done in the timekeeping has some overflow
protection that limits the max shift value. That means it will take
more then shift loops to accumulate all of the cycles. This causes
the shift decrement to underflow, which causes the loop to never exit.

The simplest fix would be simply to do a:
	if (shift)
		shift--;

However that is not optimal, as we know the cycle offset is larger
then the interval << shift, the above would make shift drop to zero,
then we would be spinning for quite awhile accumulating at interval
chunks at a time.

Instead, this patch only decreases shift if the offset is smaller
then cycle_interval << shift.  This makes sure we accumulate using
the largest chunks possible without overflowing tick_length, and limits
the number of iterations through the loop.

This issue was found and reported by Sonic Zhang, who also tested the fix.
Many thanks your explanation and testing!

Reported-by: Sonic Zhang <sonic.adi@gmail.com>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Sonic Zhang <sonic.adi@gmail.com>
LKML-Reference: <1268948850-5225-1-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-03-23 16:41:01 +01:00
Colin Ian King
8c2eb4805d softlockup: Stop spurious softlockup messages due to overflow
Ensure additions on touch_ts do not overflow.  This can occur
when the top 32 bits of the TSC reach 0xffffffff causing
additions to touch_ts to overflow and this in turn generates
spurious softlockup warnings.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: <stable@kernel.org>
LKML-Reference: <1268994482.1798.6.camel@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-21 19:30:13 +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
KOSAKI Motohiro
8bc037fb89 sched: Use proper type in sched_getaffinity()
Using the proper type fixes the following compiler warning:

  kernel/sched.c:4850: warning: comparison of distinct pointer types lacks a cast

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: torvalds@linux-foundation.org
Cc: travis@sgi.com
Cc: peterz@infradead.org
Cc: drepper@redhat.com
Cc: rja@sgi.com
Cc: sharyath@in.ibm.com
Cc: steiner@sgi.com
LKML-Reference: <20100317090046.4C79.A69D9226@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-17 10:48:49 +01:00
Andrew Morton
c890692bf3 kernel/sched.c: Suppress unused var warning
On UP:

  kernel/sched.c: In function 'wake_up_new_task':
  kernel/sched.c:2631: warning: unused variable 'cpu'

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-16 11:13:42 +01:00
Paul E. McKenney
e3818b8dce rcu: Make rcu_read_lock_bh_held() allow for disabled BH
Disabling BH can stand in for rcu_read_lock_bh(), and this patch
updates rcu_read_lock_bh_held() to allow for this.  In order to
avoid include-file hell, this function is moved out of line to
kernel/rcupdate.c.

This fixes a false positive RCU warning.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Lai Jiangshan <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: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <20100316000343.GA25857@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-16 09:57:49 +01:00
KOSAKI Motohiro
cd3d8031eb sched: sched_getaffinity(): Allow less than NR_CPUS length
[ Note, this commit changes the syscall ABI for > 1024 CPUs systems. ]

Recently, some distro decided to use NR_CPUS=4096 for mysterious reasons.
Unfortunately, glibc sched interface has the following definition:

	# define __CPU_SETSIZE  1024
	# define __NCPUBITS     (8 * sizeof (__cpu_mask))
	typedef unsigned long int __cpu_mask;
	typedef struct
	{
	  __cpu_mask __bits[__CPU_SETSIZE / __NCPUBITS];
	} cpu_set_t;

It mean, if NR_CPUS is bigger than 1024, cpu_set_t makes an
ABI issue ...

More recently, Sharyathi Nagesh reported following test program makes
misterious syscall failure:

 -----------------------------------------------------------------------
 #define _GNU_SOURCE
 #include<stdio.h>
 #include<errno.h>
 #include<sched.h>

 int main()
 {
     cpu_set_t set;
     if (sched_getaffinity(0, sizeof(cpu_set_t), &set) < 0)
         printf("\n Call is failing with:%d", errno);
 }
 -----------------------------------------------------------------------

Because the kernel assumes len argument of sched_getaffinity() is bigger
than NR_CPUS. But now it is not correct.

Now we are faced with the following annoying dilemma, due to
the limitations of the glibc interface built in years ago:

 (1) if we change glibc's __CPU_SETSIZE definition, we lost
     binary compatibility of _all_ application.

 (2) if we don't change it, we also lost binary compatibility of
     Sharyathi's use case.

Then, I would propse to change the rule of the len argument of
sched_getaffinity().

Old:
	len should be bigger than NR_CPUS
New:
	len should be bigger than maximum possible cpu id

This creates the following behavior:

 (A) In the real 4096 cpus machine, the above test program still
     return -EINVAL.

 (B) NR_CPUS=4096 but the machine have less than 1024 cpus (almost
     all machines in the world), the above can run successfully.

Fortunatelly, BIG SGI machine is mainly used for HPC use case. It means
they can rebuild their programs.

IOW we hope they are not annoyed by this issue ...

Reported-by: Sharyathi Nagesh <sharyath@in.ibm.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Mike Travis <travis@sgi.com>
LKML-Reference: <20100312161316.9520.A69D9226@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-15 08:28:44 +01:00
Linus Torvalds
80a186074e Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Fix pick_next_highest_task_rt() for cgroups
  sched: Cleanup: remove unused variable in try_to_wake_up()
  x86: Fix sched_clock_cpu for systems with unsynchronized TSC
2010-03-13 14:46:18 -08:00
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
Linus Torvalds
9fdfbc2bff 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: Provide generic perf_sample_data initialization
  MAINTAINERS: Add Arnaldo as tools/perf/ co-maintainer
  perf trace: Don't use pager if scripting
  perf trace/scripting: Remove extraneous header read
  perf, ARM: Modify kuser rmb() call to compile for Thumb-2
  x86/stacktrace: Don't dereference bad frame pointers
  perf archive: Don't try to collect files without a build-id
  perf_events, x86: Fixup fixed counter constraints
  perf, x86: Restrict the ANY flag
  perf, x86: rename macro in ARCH_PERFMON_EVENTSEL_ENABLE
  perf, x86: add some IBS macros to perf_event.h
  perf, x86: make IBS macros available in perf_event.h
  hw-breakpoints: Remove stub unthrottle callback
  x86/hw-breakpoints: Remove the name field
  perf: Remove pointless breakpoint union
  perf lock: Drop the buffers multiplexing dependency
  perf lock: Fix and add misc documentally things
  percpu: Add __percpu sparse annotations to hw_breakpoint
2010-03-13 14:39:42 -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
Linus Torvalds
64d5aea300 Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  timekeeping: Prevent oops when GENERIC_TIME=n
2010-03-12 16:27:08 -08:00
Linus Torvalds
c32da02342 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (56 commits)
  doc: fix typo in comment explaining rb_tree usage
  Remove fs/ntfs/ChangeLog
  doc: fix console doc typo
  doc: cpuset: Update the cpuset flag file
  Fix of spelling in arch/sparc/kernel/leon_kernel.c no longer needed
  Remove drivers/parport/ChangeLog
  Remove drivers/char/ChangeLog
  doc: typo - Table 1-2 should refer to "status", not "statm"
  tree-wide: fix typos "ass?o[sc]iac?te" -> "associate" in comments
  No need to patch AMD-provided drivers/gpu/drm/radeon/atombios.h
  devres/irq: Fix devm_irq_match comment
  Remove reference to kthread_create_on_cpu
  tree-wide: Assorted spelling fixes
  tree-wide: fix 'lenght' typo in comments and code
  drm/kms: fix spelling in error message
  doc: capitalization and other minor fixes in pnp doc
  devres: typo fix s/dev/devm/
  Remove redundant trailing semicolons from macros
  fix typo "definetly" -> "definitely" in comment
  tree-wide: s/widht/width/g typo in comments
  ...

Fix trivial conflict in Documentation/laptops/00-INDEX
2010-03-12 16:04:50 -08:00
Dave Young
2edf5e4980 sysctl extern cleanup: lockdep
Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move lockdep extern declarations to linux/lockdep.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:53:10 -08:00
Dave Young
4f0e056fde sysctl extern cleanup: rtmutex
Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move max_lock_depth extern declaration to linux/rtmutex.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:53:10 -08:00
Dave Young
c55b7c3e82 sysctl extern cleanup: acct
Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move acct_parm extern declaration to linux/acct.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:53:10 -08:00
Dave Young
15485a4682 sysctl extern cleanup: sg
Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move sg_big_buff extern declaration to scsi/sg.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Doug Gilbert <dgilbert@interlog.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:53:10 -08:00
Dave Young
5ed109103d sysctl extern cleanup: module
Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move modprobe_path extern declaration to linux/kmod.h
Move modules_disabled extern declaration to linux/module.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:53:10 -08:00
Dave Young
e5ab67726f sysctl extern cleanup: rcu
Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move rcutorture_runnable extern declaration to linux/rcupdate.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:53:08 -08:00
Dave Young
d33ed52d57 sysctl extern cleanup: signal
Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move print_fatal_signals extern declaration to linux/signal.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:44 -08:00
Dave Young
eb5572fed5 sysctl extern cleanup: C_A_D
Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move C_A_D extern variable declaration to linux/reboot.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:44 -08:00
Alexey Dobriyan
8467005da3 nsproxy: remove INIT_NSPROXY()
Remove INIT_NSPROXY(), use C99 initializer.
Remove INIT_IPC_NS(), INIT_NET_NS() while I'm at it.

Note: headers trim will be done later, now it's quite pointless because
results will be invalidated by merge window.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:40 -08:00
Oleg Nesterov
13aa9a6b0f pid_ns: zap_pid_ns_processes: use SEND_SIG_NOINFO instead of force_sig()
zap_pid_ns_processes() uses force_sig(SIGKILL) to ensure SIGKILL will be
delivered to sub-namespace inits as well.  This is correct, but we are
going to change force_sig_info() semantics.  See
http://bugzilla.kernel.org/show_bug.cgi?id=15395#c31

We can use send_sig_info(SEND_SIG_NOINFO) instead, since
614c517d7c ("signals: SEND_SIG_NOINFO should
be considered as SI_FROMUSER()") SEND_SIG_NOINFO means "from user" and
therefore send_signal() will get the correct from_ancestor_ns = T flag.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:40 -08:00
Veaceslav Falico
93c59907c6 copy_signal() cleanup: clean thread_group_cputime_init()
Remove unneeded initializations in thread_group_cputime_init() and in
posix_cpu_timers_init_group().  They are useless after kmem_cache_zalloc()
was used in copy_signal().

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:39 -08:00
Veaceslav Falico
4dd66e69d4 copy_signal() cleanup: kill taskstats_tgid_init() and acct_init_pacct()
Kill unused functions taskstats_tgid_init() and acct_init_pacct() because
we don't use them anywhere after using kmem_cache_zalloc() in
copy_signal().

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:39 -08:00
Veaceslav Falico
a56704ef6b copy_signal() cleanup: use zalloc and remove initializations
Use kmem_cache_zalloc() on signal creation and remove unneeded
initialization lines in copy_signal().

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:39 -08:00
Kirill A. Shutemov
a0a4db548e cgroups: remove events before destroying subsystem state objects
Events should be removed after rmdir of cgroup directory, but before
destroying subsystem state objects.  Let's take reference to cgroup
directory dentry to do that.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Dan Malek <dan@embeddedalley.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:37 -08:00
Kirill A. Shutemov
4ab78683c1 cgroups: fix race between userspace and kernelspace
Notify userspace about cgroup removing only after rmdir of cgroup
directory to avoid race between userspace and kernelspace.

eventfd are used to notify about two types of event:
 - control file-specific, like crossing memory threshold;
 - cgroup removing.

To understand what really happen, userspace can check if the cgroup still
exists.  To avoid race beetween userspace and kernelspace we have to
notify userspace about cgroup removing only after rmdir of cgroup
directory.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Dan Malek <dan@embeddedalley.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:37 -08:00
Kirill A. Shutemov
0dea116876 cgroup: implement eventfd-based generic API for notifications
This patchset introduces eventfd-based API for notifications in cgroups
and implements memory notifications on top of it.

It uses statistics in memory controler to track memory usage.

Output of time(1) on building kernel on tmpfs:

Root cgroup before changes:
	make -j2  506.37 user 60.93s system 193% cpu 4:52.77 total
Non-root cgroup before changes:
	make -j2  507.14 user 62.66s system 193% cpu 4:54.74 total
Root cgroup after changes (0 thresholds):
	make -j2  507.13 user 62.20s system 193% cpu 4:53.55 total
Non-root cgroup after changes (0 thresholds):
	make -j2  507.70 user 64.20s system 193% cpu 4:55.70 total
Root cgroup after changes (1 thresholds, never crossed):
	make -j2  506.97 user 62.20s system 193% cpu 4:53.90 total
Non-root cgroup after changes (1 thresholds, never crossed):
	make -j2  507.55 user 64.08s system 193% cpu 4:55.63 total

This patch:

Introduce the write-only file "cgroup.event_control" in every cgroup.

To register new notification handler you need:
- create an eventfd;
- open a control file to be monitored. Callbacks register_event() and
  unregister_event() must be defined for the control file;
- write "<event_fd> <control_fd> <args>" to cgroup.event_control.
  Interpretation of args is defined by control file implementation;

eventfd will be woken up by control file implementation or when the
cgroup is removed.

To unregister notification handler just close eventfd.

If you need notification functionality for a control file you have to
implement callbacks register_event() and unregister_event() in the
struct cftype.

[kamezawa.hiroyu@jp.fujitsu.com: Kconfig fix]
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Dan Malek <dan@embeddedalley.com>
Cc: Vladislav Buzov <vbuzov@embeddedalley.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Alexander Shishkin <virtuoso@slind.org>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:37 -08:00
Li Zefan
b70cc5fdb4 cgroups: clean up cgroup_pidlist_find() a bit
Don't call get_pid_ns() before we locate/alloc the ns.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Acked-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:36 -08:00