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author | Yabin Cui <yabinc@google.com> | 2017-06-01 23:36:09 +0000 |
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committer | android-build-merger <android-build-merger@google.com> | 2017-06-01 23:36:09 +0000 |
commit | df104e1ed80c87b26b2e4652c2631d0f66137589 (patch) | |
tree | a75ee11953caa54ae80a8fd4b94db9e6c7b819b3 | |
parent | 7ac7c486dfbc7b130b348e694e6ba9a581ea7481 (diff) | |
parent | 668878b3b73878edb9bcf960bd44cc07ec136cb0 (diff) | |
download | extras-df104e1ed80c87b26b2e4652c2631d0f66137589.tar.gz |
Merge "simpleperf: write -1 to perf_event_paranoid when running as root."
am: 668878b3b7
Change-Id: I46bbb7af11b38538384243ba91d30204def53a13
-rw-r--r-- | simpleperf/environment.cpp | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/simpleperf/environment.cpp b/simpleperf/environment.cpp index d0cb8351..7fff85f1 100644 --- a/simpleperf/environment.cpp +++ b/simpleperf/environment.cpp @@ -361,8 +361,11 @@ static const char* GetLimitLevelDescription(int limit_level) { } bool CheckPerfEventLimit() { - // root is not limited by /proc/sys/kernel/perf_event_paranoid. - if (IsRoot()) { + // Root is not limited by /proc/sys/kernel/perf_event_paranoid. However, the monitored threads + // may create child processes not running as root. To make sure the child processes have + // enough permission to create inherited tracepoint events, write -1 to perf_event_paranoid. + // See http://b/62230699. + if (IsRoot() && android::base::WriteStringToFile("-1", "/proc/sys/kernel/perf_event_paranoid")) { return true; } int limit_level; |