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authorBen Hutchings <ben@decadent.org.uk>2016-01-19 21:35:15 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-01-26 11:52:45 -0300
commit3379e0c3effa87d7734fc06277a7023292aadb0c (patch)
treebc9e36c1019d6150f6215a7ae580eb44f61766da /tools/perf/util/evsel.c
parentperf hists: Cleanup filtering functions (diff)
downloadlinux-dev-3379e0c3effa87d7734fc06277a7023292aadb0c.tar.xz
linux-dev-3379e0c3effa87d7734fc06277a7023292aadb0c.zip
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>
Diffstat (limited to 'tools/perf/util/evsel.c')
-rw-r--r--tools/perf/util/evsel.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index cdbaf9b51e42..467808680ee4 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2362,12 +2362,15 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
case EPERM:
case EACCES:
return scnprintf(msg, size,
- "You may not have permission to collect %sstats.\n"
- "Consider tweaking /proc/sys/kernel/perf_event_paranoid:\n"
- " -1 - Not paranoid at all\n"
- " 0 - Disallow raw tracepoint access for unpriv\n"
- " 1 - Disallow cpu events for unpriv\n"
- " 2 - Disallow kernel profiling for unpriv",
+ "You may not have permission to collect %sstats.\n\n"
+ "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n"
+ "which controls use of the performance events system by\n"
+ "unprivileged users (without CAP_SYS_ADMIN).\n\n"
+ "The default value is 1:\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"
+ ">= 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 " : "");
case ENOENT:
return scnprintf(msg, size, "The %s event is not supported.",