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author | Yabin Cui <yabinc@google.com> | 2017-06-01 23:46:25 +0000 |
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committer | android-build-merger <android-build-merger@google.com> | 2017-06-01 23:46:25 +0000 |
commit | f55d48bf08896463bb99883c527069c8027097ce (patch) | |
tree | 416a772fc695c769e64d83021f8d025a1941635b | |
parent | 1c7a854e5fa68b76a308b57b683c293c56daf544 (diff) | |
parent | 6ec981b750d54bae4053f8418b6de39747f63e70 (diff) | |
download | extras-f55d48bf08896463bb99883c527069c8027097ce.tar.gz |
Merge "simpleperf: write -1 to perf_event_paranoid when running as root." am: 668878b3b7 am: df104e1ed8
am: 6ec981b750
Change-Id: I5ed1c31bb336bb060d228e1866d8b0c8cd5d9816
-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; |