From 27db78307481dbba68c5f3563c6cb694b25521d9 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Sat, 14 Dec 2013 20:31:56 -0800 Subject: perf bench: Add futex-wake microbenchmark Block a bunch of threads on a futex and wake them up, N at a time. This program is particularly useful to measure the latency of nthread wakeups in non-error situations: all waiters are queued and all wake calls wakeup one or more tasks. An example run: $ perf bench futex wake -t 512 -r 100 Run summary [PID 27823]: blocking on 512 threads (at futex 0x7e10d4), waking up 1 at a time. [Run 1]: Wokeup 512 of 512 threads in 6.0080 ms [Run 2]: Wokeup 512 of 512 threads in 5.2280 ms [Run 3]: Wokeup 512 of 512 threads in 4.8300 ms ... [Run 100]: Wokeup 512 of 512 threads in 5.0100 ms Wokeup 512 of 512 threads in 5.0109 ms (+-2.25%) Signed-off-by: Davidlohr Bueso Acked-by: Darren Hart Cc: Aswin Chandramouleeswaran Cc: Darren Hart Cc: Ingo Molnar Cc: Jason Low Cc: Peter Zijlstra Cc: Scott J Norton Cc: Thomas Gleixner Cc: Waiman Long Link: http://lkml.kernel.org/r/1387081917-9102-3-git-send-email-davidlohr@hp.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-bench.c | 1 + 1 file changed, 1 insertion(+) (limited to 'tools/perf/builtin-bench.c') diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c index a8b0138fc6a0..743a30a8baa0 100644 --- a/tools/perf/builtin-bench.c +++ b/tools/perf/builtin-bench.c @@ -57,6 +57,7 @@ static struct bench mem_benchmarks[] = { static struct bench futex_benchmarks[] = { { "hash", "Benchmark for futex hash table", bench_futex_hash }, + { "wake", "Benchmark for futex wake calls", bench_futex_wake }, { "all", "Test all futex benchmarks", NULL }, { NULL, NULL, NULL } }; -- cgit v1.2.3