p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

perf tools: Document the perf sysctls 

perf_event_paranoid was only documented in source code and a perf error
message.  Copy the documentation from the error message to
Documentation/sysctl/kernel.txt.

perf_cpu_time_max_percent was already documented but missing from the
list at the top, so add it there.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20160119213515.GG2637@decadent.org.uk
[ Remove reference to external Documentation file, provide info inline, as before ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ben Hutchings 2016-01-19 21:35:15 +00:00 committed by Arnaldo Carvalho de Melo
parent 1f7c254132
commit 3379e0c3ef
2 changed files with 22 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
Documentation/sysctl/kernel.txt
View File

@ -58,6 +58,8 @@ show up in /proc/sys/kernel:
- panic_on_stackoverflow - panic_on_stackoverflow
- panic_on_unrecovered_nmi - panic_on_unrecovered_nmi
- panic_on_warn - panic_on_warn
- perf_cpu_time_max_percent
- perf_event_paranoid
- pid_max - pid_max
- powersave-nap [ PPC only ] - powersave-nap [ PPC only ]
- printk - printk
@ -639,6 +641,17 @@ allowed to execute.
============================================================== ==============================================================
perf_event_paranoid:
Controls use of the performance events system by unprivileged
users (without CAP_SYS_ADMIN). The default value is 1.
-1: Allow use of (almost) all events by all users
>=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
>=1: Disallow CPU event access by users without CAP_SYS_ADMIN
>=2: Disallow kernel profiling by users without CAP_SYS_ADMIN
==============================================================
pid_max: pid_max:

15
tools/perf/util/evsel.c
View File

@ -2362,12 +2362,15 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
case EPERM: case EPERM:
case EACCES: case EACCES:
return scnprintf(msg, size, return scnprintf(msg, size,
"You may not have permission to collect %sstats.\n" "You may not have permission to collect %sstats.\n\n"
"Consider tweaking /proc/sys/kernel/perf_event_paranoid:\n" "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n"
" -1 - Not paranoid at all\n" "which controls use of the performance events system by\n"
" 0 - Disallow raw tracepoint access for unpriv\n" "unprivileged users (without CAP_SYS_ADMIN).\n\n"
" 1 - Disallow cpu events for unpriv\n" "The default value is 1:\n\n"
" 2 - Disallow kernel profiling for unpriv", " -1: Allow use of (almost) all events by all users\n"
">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n"
">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN",
target->system_wide ? "system-wide " : ""); target->system_wide ? "system-wide " : "");
case ENOENT: case ENOENT:
return scnprintf(msg, size, "The %s event is not supported.", return scnprintf(msg, size, "The %s event is not supported.",