Commit ac0bb6b7 authored by Konstantin Khlebnikov's avatar Konstantin Khlebnikov Committed by Arnaldo Carvalho de Melo
Browse files

perf: Fix documentation for sysctls perf_event_paranoid and perf_event_mlock_kb 



Fix misprint CAP_IOC_LOCK -> CAP_IPC_LOCK. This capability have nothing
to do with raw tracepoints. This part is about bypassing mlock limits.

Sysctl kernel.perf_event_paranoid = -1 allows raw and ftrace function
tracepoints without CAP_SYS_ADMIN.

Signed-off-by: default avatarKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/150322916080.129746.11285255474738558340.stgit@buzz


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 2826478a

Documentation/sysctl/kernel.txt

+12 −1
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ show up in /proc/sys/kernel: 
- perf_cpu_time_max_percent

- perf_event_paranoid

- perf_event_max_stack

- perf_event_mlock_kb

- perf_event_max_contexts_per_stack

- pid_max

- powersave-nap               [ PPC only ]
@@ -654,7 +655,9 @@ Controls use of the performance events system by unprivileged 
users (without CAP_SYS_ADMIN).  The default value is 2.



 -1: Allow use of (almost) all events by all users

>=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK

     Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK

>=0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN

     Disallow raw tracepoint access by users without CAP_SYS_ADMIN

>=1: Disallow CPU event access by users without CAP_SYS_ADMIN

>=2: Disallow kernel profiling by users without CAP_SYS_ADMIN
@@ -673,6 +676,14 @@ The default value is 127. 


==============================================================



perf_event_mlock_kb:



Control size of per-cpu ring buffer not counted agains mlock limit.



The default value is 512 + 1 page



==============================================================



perf_event_max_contexts_per_stack:



Controls maximum number of stack frame context entries for

tools/perf/util/evsel.c

+3 −1
Original line number Diff line number Diff line
@@ -2674,7 +2674,9 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target, 
		 "unprivileged users (without CAP_SYS_ADMIN).\n\n"

		 "The current value is %d:\n\n"

		 "  -1: Allow use of (almost) all events by all users\n"

		 ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n"

		 "      Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK\n"

		 ">= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN\n"

		 "      Disallow raw tracepoint access by users without CAP_SYS_ADMIN\n"

		 ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"

		 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n"

		 "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"

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