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| author | Davidlohr Bueso <davidlohr@hp.com> | 2013-12-14 20:31:57 -0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2014-03-14 11:20:44 -0300 |
| commit | 0fb298cf95c0d8119557b7d4657724a146e0622e (patch) | |
| tree | 373a4bd7d4117fd6e49d0750fb709368631594e5 /tools/perf/bench/futex.h | |
| parent | 27db78307481dbba68c5f3563c6cb694b25521d9 (diff) | |
| download | linux-0fb298cf95c0d8119557b7d4657724a146e0622e.tar.bz2 | |
perf bench: Add futex-requeue microbenchmark
Block a bunch of threads on a futex and requeue them on another, N at a
time.
This program is particularly useful to measure the latency of nthread
requeues without waking up any tasks -- thus mimicking a regular
futex_wait.
An example run:
$ perf bench futex requeue -r 100 -t 64
Run summary [PID 151011]: Requeuing 64 threads (from 0x7d15c4 to 0x7d15c8), 1 at a time.
[Run 1]: Requeued 64 of 64 threads in 0.0400 ms
[Run 2]: Requeued 64 of 64 threads in 0.0390 ms
[Run 3]: Requeued 64 of 64 threads in 0.0400 ms
...
[Run 100]: Requeued 64 of 64 threads in 0.0390 ms
Requeued 64 of 64 threads in 0.0399 ms (+-0.37%)
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/r/1387081917-9102-4-git-send-email-davidlohr@hp.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/bench/futex.h')
| -rw-r--r-- | tools/perf/bench/futex.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/tools/perf/bench/futex.h b/tools/perf/bench/futex.h index 6ac45093fac4..71f2844cf97f 100644 --- a/tools/perf/bench/futex.h +++ b/tools/perf/bench/futex.h @@ -55,4 +55,17 @@ futex_wake(u_int32_t *uaddr, int nr_wake, int opflags) return futex(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags); } +/** +* futex_cmp_requeue() - requeue tasks from uaddr to uaddr2 +* @nr_wake: wake up to this many tasks +* @nr_requeue: requeue up to this many tasks +*/ +static inline int +futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake, + int nr_requeue, int opflags) +{ + return futex(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2, + val, opflags); +} + #endif /* _FUTEX_H */ |