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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: Konstantin 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: Arnaldo Carvalho de Melo <acme@redhat.com>
zero-colors
Konstantin Khlebnikov 2017-08-20 14:39:20 +03:00 committed by Arnaldo Carvalho de Melo
parent 2826478a66
commit ac0bb6b72f
2 changed files with 15 additions and 2 deletions
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13
Documentation/sysctl/kernel.txt
View File

@ -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

4
tools/perf/util/evsel.c
View File

@ -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"