diff options
Diffstat (limited to 'tools/perf/Documentation/perf-lock.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-lock.txt | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/tools/perf/Documentation/perf-lock.txt b/tools/perf/Documentation/perf-lock.txt index f5938d616d75..c17b3e318169 100644 --- a/tools/perf/Documentation/perf-lock.txt +++ b/tools/perf/Documentation/perf-lock.txt @@ -111,11 +111,11 @@ INFO OPTIONS -t:: --threads:: - dump thread list in perf.data + dump only the thread list in perf.data -m:: --map:: - dump map of lock instances (address:name table) + dump only the map of lock instances (address:name table) CONTENTION OPTIONS @@ -179,16 +179,17 @@ CONTENTION OPTIONS -o:: --lock-owner:: - Show lock contention stat by owners. Implies --threads and - requires --use-bpf. + Show lock contention stat by owners. This option can be combined with -t, + which shows owner's per thread lock stats, or -v, which shows owner's + stacktrace. Requires --use-bpf. -Y:: --type-filter=<value>:: Show lock contention only for given lock types (comma separated list). Available values are: semaphore, spinlock, rwlock, rwlock:R, rwlock:W, rwsem, rwsem:R, rwsem:W, - rtmutex, rwlock-rt, rwlock-rt:R, rwlock-rt:W, pcpu-sem, pcpu-sem:R, pcpu-sem:W, - mutex + rtmutex, rwlock-rt, rwlock-rt:R, rwlock-rt:W, percpu-rwmem, pcpu-sem, + pcpu-sem:R, pcpu-sem:W, mutex Note that RW-variant of locks have :R and :W suffix. Names without the suffix are shortcuts for the both variants. Ex) rwsem = rwsem:R + rwsem:W. @@ -215,6 +216,21 @@ CONTENTION OPTIONS --cgroup-filter=<value>:: Show lock contention only in the given cgroups (comma separated list). +-J:: +--inject-delay=<time@function>:: + Add delays to the given lock. It's added to the contention-end part so + that the (new) owner of the lock will be delayed. But by slowing down + the owner, the waiters will also be delayed as well. This is working + only with -b/--use-bpf. + + The 'time' is specified in nsec but it can have a unit suffix. Available + units are "ms", "us" and "ns". Currently it accepts up to 10ms of delays + for safety reasons. + + Note that it will busy-wait after it gets the lock. Delaying locks can + have significant consequences including potential kernel crashes. Please + use it at your own risk. + SEE ALSO -------- |