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authorDavidlohr Bueso2015-05-08 11:37:59 -0700
committerArnaldo Carvalho de Melo2015-05-08 16:23:50 -0300
commitd65817b4e707068c2dd3e002e87c2a0294aabc2c (patch)
treec744c2450c306e1770c55131583db85d1fbbdc8e /tools/perf/Documentation
parentb91fc39f4ad7503419dd617df78401fa36266cb3 (diff)
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/Documentation')
-rw-r--r--tools/perf/Documentation/perf-bench.txt3
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-bench.txt b/tools/perf/Documentation/perf-bench.txt
index f6480cbf309b..bf3d0644bf10 100644
--- a/tools/perf/Documentation/perf-bench.txt
+++ b/tools/perf/Documentation/perf-bench.txt
@@ -210,6 +210,9 @@ Suite for evaluating hash tables.
*wake*::
Suite for evaluating wake calls.
+*wake-parallel*::
+Suite for evaluating parallel wake calls.
+
*requeue*::
Suite for evaluating requeue calls.