Intel OpenBMC Linux kernel source tree (mirror) https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev 2015-05-08T19:23:50+00:00 2015-05-08T19:23:50+00:00 Davidlohr Bueso dave@stgolabs.net 2015-05-08T18:37:59+00:00 urn:sha1:d65817b4e707068c2dd3e002e87c2a0294aabc2c 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>