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authorDavidlohr Bueso <dave@stgolabs.net>2014-09-29 09:41:08 -0700
committerArnaldo Carvalho de Melo <acme@redhat.com>2014-09-29 15:43:26 -0300
commite19685ed24b518440c0717719ff02e74c0e6d2cb (patch)
tree8753b39b7d2ca95b45304b14cc6e4e87f84fd0a4 /tools/perf
parent86c87e13f8a5dffc6cc7b0f37340f815dc172945 (diff)
downloadlinux-e19685ed24b518440c0717719ff02e74c0e6d2cb.tar.gz
perf bench futex: Sanitize -q option in requeue
When given the number of threads to requeue at once by user input, there's always the risk of this value being larger than the total number of threads. This doesn't make any sense, and the kernel can easily deal with such sort of situations, hence no big deal. We should however prevent bogus output such as: ./perf bench --repeat 2 futex requeue -q 10 Run summary [PID 22210]: Requeuing 4 threads (from [private] 0x99ef3c to 0x99ef38), 10 at a time. [Run 1]: Requeued 10 of 4 threads in 0.0040 ms [Run 2]: Requeued 10 of 4 threads in 0.0030 ms Requeued 10 of 4 threads in 0.0035 ms (+-14.29%) Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Davidlohr Bueso <dbueso@suse.de> Link: http://lkml.kernel.org/r/1412008868-22328-2-git-send-email-dave@stgolabs.net Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/bench/futex-requeue.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/tools/perf/bench/futex-requeue.c b/tools/perf/bench/futex-requeue.c
index 9837a8831406..bedff6b5b3cf 100644
--- a/tools/perf/bench/futex-requeue.c
+++ b/tools/perf/bench/futex-requeue.c
@@ -172,6 +172,9 @@ int bench_futex_requeue(int argc, const char **argv,
gettimeofday(&end, NULL);
timersub(&end, &start, &runtime);
+ if (nrequeued > nthreads)
+ nrequeued = nthreads;
+
update_stats(&requeued_stats, nrequeued);
update_stats(&requeuetime_stats, runtime.tv_usec);
@@ -190,7 +193,6 @@ int bench_futex_requeue(int argc, const char **argv,
if (ret)
err(EXIT_FAILURE, "pthread_join");
}
-
}
/* cleanup & report results */