leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
c5dfd78eb7
linux/arch/arm/kernel
History
Arnaldo Carvalho de Melo c5dfd78eb7 perf core: Allow setting up max frame stack depth via sysctl 
The default remains 127, which is good for most cases, and not even hit
most of the time, but then for some cases, as reported by Brendan, 1024+
deep frames are appearing on the radar for things like groovy, ruby.

And in some workloads putting a _lower_ cap on this may make sense. One
that is per event still needs to be put in place tho.

The new file is:

  # cat /proc/sys/kernel/perf_event_max_stack
  127

Chaging it:

  # echo 256 > /proc/sys/kernel/perf_event_max_stack
  # cat /proc/sys/kernel/perf_event_max_stack
  256

But as soon as there is some event using callchains we get:

  # echo 512 > /proc/sys/kernel/perf_event_max_stack
  -bash: echo: write error: Device or resource busy
  #

Because we only allocate the callchain percpu data structures when there
is a user, which allows for changing the max easily, its just a matter
of having no callchain users at that point.

Reported-and-Tested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/20160426002928.GB16708@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-27 10:20:39 -03:00
..
.gitignore
arch_timer.c arch_timer: Move to generic sched_clock framework 2013-10-09 16:54:10 -07:00
armksyms.c ARM: 8479/2: add implementation for arm-smccc 2016-01-04 16:24:34 +00:00
asm-offsets.c ARM: KVM: Remove unused hyp_pc field 2016-02-29 18:34:15 +00:00
atags_compat.c ARM: convert printk(KERN_* to pr_* 2014-11-21 15:24:50 +00:00
atags_parse.c ARM: convert printk(KERN_* to pr_* 2014-11-21 15:24:50 +00:00
atags_proc.c ARM: convert printk(KERN_* to pr_* 2014-11-21 15:24:50 +00:00
atags.h ARM: 8495/1: ATAGS: move save_atags() to arch/arm/include/asm/setup.h 2016-01-04 11:26:00 +00:00
bios32.c ARM/PCI: Move align_resource function pointer to pci_host_bridge structure 2015-11-25 13:23:38 -06:00
calls.S ARM: wire up preadv2 and pwritev2 syscalls 2016-04-07 21:57:02 +01:00
cpuidle.c ARM: 8485/1: cpuidle: remove cpu parameter from the cpuidle_ops suspend hook 2015-12-22 12:09:43 +00:00
crash_dump.c ARM: 8012/1: kdump: Avoid overflow when converting pfn to physaddr 2014-04-07 12:10:00 +01:00
debug.S ARM: unify MMU/!MMU addruart calls 2015-05-20 23:09:51 +02:00
devtree.c ARM: make default platform work for NOMMU 2015-12-17 17:45:47 +01:00
dma-isa.c ARM: convert printk(KERN_* to pr_* 2014-11-21 15:24:50 +00:00
dma.c ARM: convert printk(KERN_* to pr_* 2014-11-21 15:24:50 +00:00
early_printk.c
efi.c ARM: wire up UEFI init and runtime support 2015-12-13 19:18:30 +01:00
elf.c
entry-armv.S ARM: 8515/2: move .vectors and .stubs sections back into the kernel VMA 2016-02-11 15:33:39 +00:00
entry-common.S Merge branch 'uaccess' into fixes 2015-09-11 19:18:28 +01:00
entry-ftrace.S ARM: replace BSYM() with badr assembly macro 2015-05-08 17:33:50 +01:00
entry-header.S ARM: entry: provide uaccess assembly macro hooks 2015-08-26 20:27:02 +01:00
entry-v7m.S ARM: 8450/1: v7-M: Use ret_to_user_from_irq in PendSV handler 2015-11-16 18:34:37 +00:00
fiq.c ARM: convert printk(KERN_* to pr_* 2014-11-21 15:24:50 +00:00
fiqasm.S ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ 2014-07-18 12:29:04 +01:00
ftrace.c ARM: kprobes: enable OPTPROBES for ARM 32 2015-01-13 16:10:17 +00:00
head-common.S ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ 2014-07-18 12:29:04 +01:00
head-nommu.S ARM: 8383/1: nommu: avoid deprecated source register on mov 2015-06-12 21:18:48 +01:00
head.S Merge branch 'uaccess' into fixes 2015-09-11 19:18:28 +01:00
hibernate.c ARM: use virt_to_idmap() for soft_restart() 2016-02-08 15:48:32 +00:00
hw_breakpoint.c perf/core: Set event's default ::overflow_handler() 2016-03-31 10:30:47 +02:00
hyp-stub.S ARM: 8527/1: virt: enable GICv3 system registers 2016-02-16 16:33:02 +00:00
insn.c
io.c ARM: io.c: clean up EXPORT_SYMBOL()s 2014-11-21 15:25:02 +00:00
irq.c ARM: 8499/1: irq: l2c: do not print error in case of missing l2c from 2016-01-26 23:49:02 +00:00
isa.c arm: convert use of typedef ctl_table to struct ctl_table 2014-06-06 16:08:15 -07:00
iwmmxt.S ARM: 8221/1: PJ4: allow building in Thumb-2 mode 2014-12-03 16:08:00 +00:00
jump_label.c jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP} 2015-08-03 11:34:12 +02:00
kgdb.c ARM: 8428/1: kgdb: Fix registers on sleeping tasks 2015-10-03 16:36:45 +01:00
machine_kexec.c ARM: use virt_to_idmap() for soft_restart() 2016-02-08 15:48:32 +00:00
Makefile ARM: 8534/1: virt: fix hyp-stub build for pre-ARMv7 CPUs 2016-02-22 11:39:41 +00:00
module-plts.c module: use a structure to encapsulate layout. 2015-12-04 22:46:25 +01:00
module.c ARM: 8518/1: Use correct symbols for XIP_KERNEL 2016-02-11 15:43:14 +00:00
module.lds ARM: 8220/1: allow modules outside of bl range 2015-05-08 10:42:34 +01:00
opcodes.c
paravirt.c arm: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops 2015-12-21 14:40:54 +00:00
patch.c ARM: probes: move all probe code to dedicate directory 2015-01-09 09:36:50 +00:00
perf_callchain.c perf core: Allow setting up max frame stack depth via sysctl 2016-04-27 10:20:39 -03:00
perf_event_v6.c arm: perf: factor arm_pmu core out to drivers 2015-07-31 15:01:14 +01:00
perf_event_v7.c ARM: perf: Set ARMv7 SDER SUNIDEN bit 2016-01-25 18:37:44 +00:00
perf_event_xscale.c arm: perf: factor arm_pmu core out to drivers 2015-07-31 15:01:14 +01:00
perf_regs.c perf: Move task_pt_regs sampling into arch code 2015-01-09 11:12:28 +01:00
pj4-cp0.c ARM: 8452/3: PJ4: make coprocessor access sequences buildable in Thumb2 mode 2016-01-04 11:12:10 +00:00
process.c ARM: report proper DACR value in oops dumps 2015-12-04 19:20:48 +00:00
psci_smp.c ARM: use const and __initconst for smp_operations 2015-12-01 22:17:45 +01:00
ptrace.c Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
reboot.c ARM: make virt_to_idmap() return unsigned long 2016-02-08 15:47:28 +00:00
reboot.h ARM: move reboot code to arch/arm/kernel/reboot.c 2015-04-02 09:50:45 +01:00
relocate_kernel.S ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ 2014-07-18 12:29:04 +01:00
return_address.c ARM: 8328/1: remove empty preprocessor #else branch 2015-03-28 16:54:53 +00:00
setup.c ARM: 8550/1: protect idiv patching against undefined gcc behavior 2016-04-07 21:57:02 +01:00
signal.c Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2015-09-19 21:05:02 -07:00
sigreturn_codes.S ARM: 7895/1: signal: fix armv7-m build issue in sigreturn_codes.S 2013-11-30 22:21:00 +00:00
sleep.S ARM: fix new BSYM() usage introduced via for-arm-soc branch 2015-06-12 21:19:35 +01:00
smccc-call.S ARM: 8479/2: add implementation for arm-smccc 2016-01-04 16:24:34 +00:00
smp_scu.c ARM: 8122/1: smp_scu: enable SCU standby support 2014-08-02 08:51:53 +01:00
smp_tlb.c ARM: 8111/1: Enable erratum 798181 for Broadcom Brahma-B15 2014-07-24 14:40:26 +01:00
smp_twd.c ARM: clean up TWD after previous patch 2015-10-09 16:22:53 +01:00
smp.c arch/hotplug: Call into idle with a proper state 2016-03-01 20:36:57 +01:00
stacktrace.c ARM: 8172/1: Use current_stack_pointer in save_stack_trace_tsk 2014-11-13 23:58:03 +00:00
suspend.c ARM: 8248/1: pm: remove outdated comment 2015-01-21 15:58:57 +00:00
swp_emulate.c ARM: 8475/1: SWP emulation: Restore original *data when failed 2015-12-15 11:51:42 +00:00
sys_arm.c
sys_oabi-compat.c [PATCH] arm: fix handling of F_OFD_... in oabi_fcntl64() 2015-12-29 13:04:21 -05:00
tcm.c ARM: 8388/1: tcm: Don't crash when TCM banks are protected by TrustZone 2015-06-06 10:37:28 +01:00
thumbee.c ARM: convert printk(KERN_* to pr_* 2014-11-21 15:24:50 +00:00
time.c clocksource: cosmetic: Drop OF 'dependency' from symbols 2015-10-01 02:18:39 +02:00
topology.c ARM: 8497/1: initialize cpu_scale to its default 2016-01-26 23:49:02 +00:00
traps.c ARM: remove user cmpxchg syscall 2015-10-03 16:36:45 +01:00
unwind.c ARM: 8176/1: Use current_stack_pointer in unwind_backtrace 2014-11-13 23:58:09 +00:00
v7m.c
vdso.c ARM: 8476/1: VDSO: use PTR_ERR_OR_ZERO for vma check 2015-12-17 10:29:01 +00:00
vmlinux-xip.lds.S ARM: 8537/1: drop unused DEBUG_RODATA from XIP_KERNEL 2016-02-22 11:39:43 +00:00
vmlinux.lds.S arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
xscale-cp0.c ARM: make xscale iwmmxt code multiplatform aware 2015-12-01 21:44:24 +01:00