linux/arch/mips
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
..
alchemy MIPS: Fix misspellings in comments. 2016-04-03 12:32:09 +02:00
ar7 MIPS: ar7: use gpiochip data pointer 2016-02-19 09:51:43 +01:00
ath25 genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
ath79 MIPS: ath79: Fix the ar913x reference clock rate 2016-04-03 12:32:10 +02:00
bcm47xx FIRMWARE: Broadcom: Fix grammar of warning messages in bcm47xx_sprom.c. 2016-04-03 12:32:09 +02:00
bcm63xx Merge branch 'ib-mfd-regulator-gpio-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd into devel 2016-03-09 17:40:37 +07:00
bmips irqchips/bmips: Add bcm6345-l1 interrupt controller 2016-02-08 15:03:42 +01:00
boot MIPS: BMIPS: Fix gisb-arb compatible string for 7435 2016-04-04 15:25:32 +02:00
cavium-octeon MIPS: Fix misspellings in comments. 2016-04-03 12:32:09 +02:00
cobalt MIPS: Cobalt Don't use module_init in non-modular MTD registration. 2015-06-21 22:14:30 +02:00
configs MIPS: ci20: Enable NAND and UBIFS support in defconfig. 2016-04-03 12:32:09 +02:00
dec MIPS: Fix misspellings in comments. 2016-04-03 12:32:09 +02:00
emma
fw MIPS: Fix misspellings in comments. 2016-04-03 12:32:09 +02:00
include MIPS: traps: Correct the SIGTRAP debug ABI in do_watch' and do_trap_or_bp' 2016-04-03 12:32:09 +02:00
jazz MIPS: Jazz: Migrate to new 'set-state' interface 2015-09-03 12:07:50 +02:00
jz4740 MIPS: jz4740: Fix surviving instance of irq_to_gpio() 2016-02-29 11:23:49 +01:00
kernel perf core: Allow setting up max frame stack depth via sysctl 2016-04-27 10:20:39 -03:00
kvm MIPS: Fix misspellings in comments. 2016-04-03 12:32:09 +02:00
lantiq MIPS: Make MIPS_CMDLINE_DTB default 2015-11-11 08:38:37 +01:00
lasat [mips] switch pvc_proc_cleanup() to remove_proc_subtree() 2015-12-23 10:41:38 -05:00
lib MIPS: Cleanup the unused __arch_local_irq_restore() function 2016-01-22 01:58:49 +01:00
loongson32 MIPS: loongsoon32: Migrate to new 'set-state' interface 2015-09-03 12:07:53 +02:00
loongson64 MIPS: hpet: Choose a safe value for the ETIME check 2016-01-22 02:00:49 +01:00
math-emu MIPS: Fix misspellings in comments. 2016-04-03 12:32:09 +02:00
mm MIPS: Fix misspellings in comments. 2016-04-03 12:32:09 +02:00
mti-malta MIPS: Fix early CM probing 2016-02-09 17:18:31 +01:00
mti-sead3 LED/MIPS: Move SEAD3 LED driver to where it belongs. 2015-11-03 08:59:20 +01:00
net net: filter: make JITs zero A for SKF_AD_ALU_XOR_X 2016-01-06 00:43:52 -05:00
netlogic MIPS: Make MIPS_CMDLINE_DTB default 2015-11-11 08:38:37 +01:00
oprofile MIPS: Add cases for CPU_I6400 2015-08-26 15:23:03 +02:00
paravirt MIPS: SMP: Don't increment irq_count multiple times for call function IPIs 2015-08-03 09:25:12 +02:00
pci PCI changes for the v4.6 merge window: 2016-03-16 14:45:55 -07:00
pic32 clk: Get rid of HAVE_MACH_CLKDEV 2016-02-25 14:41:20 -08:00
pistachio Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2015-11-15 09:10:53 -08:00
pmcs-msp71xx serial: Fix ASYNC_* => UPF_* flags misuse 2016-01-28 14:17:42 -08:00
pnx833x mips: nand: make use of mtd_to_nand() where appropriate 2015-12-08 13:03:07 -08:00
power MIPS: Hibernate: flush TLB entries earlier 2015-04-10 15:41:52 +02:00
ralink MIPS: pci: Add MT7620a PCIE driver 2016-01-20 00:39:20 +01:00
rb532 MIPS: rb532: use gpiochip data pointer 2016-02-19 09:51:44 +01:00
sgi-ip22 MIPS: ip22-gio: Remove legacy suspend/resume support 2015-02-20 13:30:55 +01:00
sgi-ip27 MIPS: Fix misspellings in comments. 2016-04-03 12:32:09 +02:00
sgi-ip32 MIPS: IP32: Fix build errors in reset code in DS1685 platform hook. 2015-05-13 00:01:41 +02:00
sibyte MIPS: Sibyte: Move bus watcher from deprecated __initcall to device_initcall 2015-09-03 12:07:49 +02:00
sni MIPS: Fix build error due to unused variables. 2015-12-22 15:21:18 +01:00
txx9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
vdso Fix ld-version.sh to handle large 3rd version part 2016-01-04 10:22:52 +01:00
vr41xx MIPS/IRQCHIP: Move irq_chip from arch/mips to drivers/irqchip. 2015-06-21 21:52:50 +02:00
xilfpga Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2015-11-15 09:10:53 -08:00
Kbuild MIPS: Initial implementation of a VDSO 2015-11-11 08:36:36 +01:00
Kbuild.platforms MIPS: Add support for PIC32MZDA platform 2016-01-24 02:53:28 +01:00
Kconfig The clk changes for this release cycle are mostly dominated by 2016-03-23 06:06:45 -07:00
Kconfig.debug MIPS: CPS: Early debug using an ns16550-compatible UART 2015-11-11 08:34:25 +01:00
Makefile MIPS: Loongson-3: Improve -march option and move it to Platform 2016-01-22 01:59:18 +01:00