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authorDavidlohr Bueso <dave@stgolabs.net>2015-05-08 21:37:59 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-05-08 22:23:50 +0300
commitd65817b4e707068c2dd3e002e87c2a0294aabc2c (patch)
treec744c2450c306e1770c55131583db85d1fbbdc8e /tools/perf/builtin-bench.c
parentb91fc39f4ad7503419dd617df78401fa36266cb3 (diff)
downloadlinux-d65817b4e707068c2dd3e002e87c2a0294aabc2c.tar.xz
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/builtin-bench.c')
-rw-r--r--tools/perf/builtin-bench.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index b9a56fa83330..b5314e452ec7 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -58,6 +58,7 @@ 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 },
+ { "wake-parallel", "Benchmark for parallel futex wake calls", bench_futex_wake_parallel },
{ "requeue", "Benchmark for futex requeue calls", bench_futex_requeue },
{ "all", "Test all futex benchmarks", NULL },
{ NULL, NULL, NULL }