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| author | Davidlohr Bueso <dave@stgolabs.net> | 2015-05-08 11:37:59 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-05-08 16:23:50 -0300 |
| commit | d65817b4e707068c2dd3e002e87c2a0294aabc2c (patch) | |
| tree | c744c2450c306e1770c55131583db85d1fbbdc8e /tools/perf/bench/bench.h | |
| parent | b91fc39f4ad7503419dd617df78401fa36266cb3 (diff) | |
| download | lwn-d65817b4e707068c2dd3e002e87c2a0294aabc2c.tar.gz lwn-d65817b4e707068c2dd3e002e87c2a0294aabc2c.zip | |
perf bench futex: Support parallel waker threads
The futex-wake benchmark only measures wakeups done within a single
process. While this has value in its own, it does not really generate
any hb->lock contention.
A new benchmark 'wake-parallel' is added, by extending the futex-wake
code such that we can measure parallel waker threads. The program output
shows the avg per-thread latency in order to complete its share of
wakeups:
Run summary [PID 13474]: blocking on 512 threads (at [private] futex 0xa88668), 8 threads waking up 64 at a time.
[Run 1]: Avg per-thread latency (waking 64/512 threads) in 0.6230 ms (+-15.31%)
[Run 2]: Avg per-thread latency (waking 64/512 threads) in 0.5175 ms (+-29.95%)
[Run 3]: Avg per-thread latency (waking 64/512 threads) in 0.7578 ms (+-18.03%)
[Run 4]: Avg per-thread latency (waking 64/512 threads) in 0.8944 ms (+-12.54%)
[Run 5]: Avg per-thread latency (waking 64/512 threads) in 1.1204 ms (+-23.85%)
Avg per-thread latency (waking 64/512 threads) in 0.7826 ms (+-9.91%)
Naturally, different combinations of numbers of blocking and waker
threads will exhibit different information.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Link: http://lkml.kernel.org/r/1431110280-20231-1-git-send-email-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/bench/bench.h')
| -rw-r--r-- | tools/perf/bench/bench.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h index 3c4dd44d45cb..70b2f718cc21 100644 --- a/tools/perf/bench/bench.h +++ b/tools/perf/bench/bench.h @@ -33,6 +33,8 @@ extern int bench_mem_memcpy(int argc, const char **argv, extern int bench_mem_memset(int argc, const char **argv, const char *prefix); extern int bench_futex_hash(int argc, const char **argv, const char *prefix); extern int bench_futex_wake(int argc, const char **argv, const char *prefix); +extern int bench_futex_wake_parallel(int argc, const char **argv, + const char *prefix); extern int bench_futex_requeue(int argc, const char **argv, const char *prefix); #define BENCH_FORMAT_DEFAULT_STR "default" |