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
..
boot	metag: enable building of all dtbs	2015-10-27 16:12:16 -05:00
configs	metag: minimal TZ1090 (Comet) SoC infrastructure	2013-06-13 12:14:07 +01:00
include	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2016-03-19 10:05:34 -07:00
kernel	perf core: Allow setting up max frame stack depth via sysctl	2016-04-27 10:20:39 -03:00
lib	metag: move EXPORT_SYMBOL(csum_partial) to metag_ksyms.c	2013-07-04 10:00:02 +01:00
mm	mm: cleanup *pte_alloc* interfaces	2016-03-17 15:09:34 -07:00
oprofile	metag: OProfile support	2013-03-15 13:21:05 +00:00
tbx	metag: handle low level kicks directly	2013-11-06 10:40:02 +00:00
Kconfig	dma-mapping: always provide the dma_map_ops based implementation	2016-01-20 17:09:18 -08:00
Kconfig.debug	consolidate per-arch stack overflow debugging options	2013-07-04 11:25:39 -07:00
Kconfig.soc	metag: tz1090: select and instantiate gpio-tz1090	2013-07-22 10:55:31 +01:00
Makefile	metag: use common make variables for dtb builds	2015-10-27 16:12:15 -05:00