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author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2014-06-10 17:18:54 -0300 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2014-06-19 16:13:12 -0300 |
commit | 5229e366ee6baeb58b77e09643d2e11cbbd29950 (patch) | |
tree | a562927b7bf32c78bca4dbe60ea39687e12d1e73 | |
parent | cdcd1e6bd8a92f8353fc2f37003c6eae2d1e6903 (diff) | |
download | linux-stable-5229e366ee6baeb58b77e09643d2e11cbbd29950.tar.gz linux-stable-5229e366ee6baeb58b77e09643d2e11cbbd29950.tar.bz2 linux-stable-5229e366ee6baeb58b77e09643d2e11cbbd29950.zip |
perf evlist: Add suggestion of how to set perf_event_paranoid sysctl
Minor hint to speed up problem resolution and get 'trace' working for
non root users.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-abdqi8km4fj9osrn70q2zj9v@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r-- | tools/perf/util/evlist.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 59ef2802fcf6..c51223ac25f4 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1214,10 +1214,11 @@ int perf_evlist__strerror_open(struct perf_evlist *evlist __maybe_unused, "For your workloads it needs to be <= 1\nHint:\t"); } printed += scnprintf(buf + printed, size - printed, - "For system wide tracing it needs to be set to -1"); + "For system wide tracing it needs to be set to -1.\n"); printed += scnprintf(buf + printed, size - printed, - ".\nHint:\tThe current value is %d.", value); + "Hint:\tTry: 'sudo sh -c \"echo -1 > /proc/sys/kernel/perf_event_paranoid\"'\n" + "Hint:\tThe current value is %d.", value); break; default: scnprintf(buf, size, "%s", emsg); |