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
i2c: mux: demux-pinctrl: Update docs to new sysfs-attributes
2016-04-07 21:13:02 +02:00
ARM: SoC 64-bit changes for v4.6
2016-03-20 15:08:45 -07:00
arm64: Add workaround for Cavium erratum 27456
2016-02-26 15:14:27 +00:00
A relatively boring cycle in the docs tree. There's a few kernel-doc
2016-01-17 11:55:07 -08:00
cpqarray: remove it from the kernel
2016-03-14 09:06:01 -06:00
Merge branch 'for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2016-03-18 20:25:49 -07:00
Documentation: cpufreq: intel_pstate: fix typo
2016-02-18 20:31:53 +01:00
crypto: doc - Use ahash
2016-02-06 15:33:11 +08:00
dm cache: make the 'mq' policy an alias for 'smq'
2016-03-10 17:12:08 -05:00
ARM: SoC fixes
2016-04-13 08:57:18 -07:00
Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
2016-03-21 13:48:00 -07:00
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
2016-03-19 16:31:54 -07:00
[media] media: change email address
2016-01-25 12:01:08 -02:00
arm64 updates for 4.6:
2016-03-17 20:03:47 -07:00
mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage
2016-04-04 10:41:08 -07:00
gpio: documenatation: fix GPIO_LOOKUP{,_IDX} documentation
2016-02-25 16:01:51 +01:00
hwmon: Create an NSA320 hardware monitoring driver
2016-03-08 18:40:49 -08:00
Doc: i2c: Fix typo in Documentation/i2c
2016-02-10 13:12:14 -07:00
staging/rdma/hfi1: Method to toggle "fast ECN" detection
2016-03-10 20:37:50 -05:00
gpio: uapi: use 0xB4 as ioctl() major
2016-03-10 16:02:52 +07:00
isdn: i4l: move active-isdn drivers to staging
2016-03-05 15:00:38 -08:00
Doc: ja_JP: Fix a typo in HOWTO
2016-02-10 13:14:37 -07:00
Documentation/ko_KR: update maintainer information
2016-02-17 14:10:39 -07:00
Char/Misc patches for 4.6-rc1
2016-03-17 13:47:50 -07:00
Merge char-misc-next into staging-next
2016-02-22 14:46:24 -08:00
switchdev: fix typo in comments/doc
2016-03-24 14:51:24 -04:00
PM / runtime: Document steps for device removal
2016-04-05 03:46:59 +02:00
cxl: Support to flash a new image on the adapter from a guest
2016-03-09 23:39:56 +11:00
Documentation: Fix int/unsigned int comparison
2016-02-17 14:09:43 -07:00
Another relatively boring cycle for the docs tree: typo fixes, translation
2016-03-17 12:09:35 -07:00
rapidio: add mport char device driver
2016-03-22 15:36:02 -07:00
st: Fix MTMKPART to work with newer drives
2016-02-23 21:27:02 -05:00
tty: Remove chars_in_buffer() line discipline method
2016-01-27 15:01:44 -08:00
Merge branch 'topic/hda-mst' into for-next
2016-02-10 09:25:15 +01:00
perf core: Allow setting up max frame stack depth via sysctl
2016-04-27 10:20:39 -03:00
target/user: Report capability of handling out-of-order completions to userspace
2016-03-10 21:49:09 -08:00
thermal: doc: Add details of devm_thermal_zone_of_sensor_{register,unregister}
2016-03-09 10:51:41 -08:00
Another relatively boring cycle for the docs tree: typo fixes, translation
2016-03-17 12:09:35 -07:00
doc: usb: Fix typo in gadget_multi documentation
2016-04-13 12:02:28 -07:00
[media] saa7134: Add support for Snazio TvPVR PRO
2016-03-03 09:03:48 -03:00
One of the largest releases for KVM... Hardly any generic improvement,
2016-03-16 09:55:35 -07:00
mm: thp: set THP defrag by default to madvise and add a stall-free defrag option
2016-03-17 15:09:34 -07:00
Merge git://www.linux-watchdog.org/linux-watchdog
2016-03-19 19:35:51 -07:00
x86/mm/pkeys: Add missing Documentation
2016-03-29 11:21:17 +02:00
Documentation: Chinese translation of arm64/silicon-errata.txt
2016-02-17 14:08:07 -07:00
Merge branch 'for-4.6-ns' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2016-03-21 10:05:13 -07:00
Documentation/CodingStyle: add space before parenthesis in example macro
2016-01-25 12:36:28 -07:00
dma-mapping: always provide the dma_map_ops based implementation
2016-01-20 17:09:18 -08:00
DMA-API: fix confusing sentence in Documentation/DMA-API.txt
2016-01-11 18:29:00 -07:00
ARM: 8506/1: common: DMA-mapping: add DMA_ATTR_ALLOC_SINGLE_PAGES attribute
2016-02-11 15:33:38 +00:00
dma-buf: Update docs for SYNC ioctl
2016-03-21 09:26:45 +01:00
Documentation: Howto: Fixed subtitles style
2016-03-09 15:30:03 -07:00
iommu/vt-d: Fix link to Intel IOMMU Specification
2016-01-29 12:32:12 +01:00
mm, kasan: SLAB support
2016-03-25 16:37:42 -07:00
kernel: add kcov code coverage
2016-03-22 15:36:02 -07:00
Documentation: translations: update linux cross reference link
2016-01-11 18:26:58 -07:00
USB: uas: Add a new NO_REPORT_LUNS quirk
2016-04-13 12:02:28 -07:00
Documentation: kselftest: Remove duplicate word
2016-03-09 15:33:38 -07:00
documentation: Clarify compiler store-fusion example
2016-03-14 15:52:19 -07:00
memory-hotplug: add automatic onlining policy for the newly added memory
2016-03-15 16:55:16 -07:00
modsign: Fix documentation on module signing enforcement parameter.
2016-03-12 01:48:11 -07:00
mm, printk: introduce new format string for flags
2016-03-15 16:55:16 -07:00
rfkill: Add documentation about LED triggers
2016-02-24 09:13:12 +01:00
rtc: implement a sysfs interface for clock offset
2016-03-14 17:08:16 +01:00
SubmittingPatches: fix spelling of "git send-email"
2016-01-25 12:30:18 -07:00
UBSAN: run-time undefined behavior sanity checker
2016-01-20 17:09:18 -08:00
c5dfd78eb7
