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path: root/tools/perf/bench/futex-requeue.c
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2015-12-17perf subcmd: Create subcmd libraryJosh Poimboeuf1-1/+1
Move the subcommand-related files from perf to a new library named libsubcmd.a. Since we're moving files anyway, go ahead and rename 'exec_cmd.*' to 'exec-cmd.*' to be consistent with the naming of all the other files. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/c0a838d4c878ab17fee50998811612b2281355c1.1450193761.git.jpoimboe@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-04-27perf bench futex: Fix hung wakeup tasks after requeueingDavidlohr Bueso1-7/+8
The futex-requeue benchmark can hang because of missing wakeups once the benchmark is done, ie: [Run 1]: Requeued 1024 of 1024 threads in 0.3290 ms perf: couldn't wakeup all tasks (135/1024) This bug, while perhaps suggesting missing wakeups in kernel futex code, is merely a consequence of the crappy FUTEX_CMP_REQUEUE man page, incorrectly mentioning that the number of requeued tasks is in fact returned, not the wakeups. This patch acknowledges this and updates the corresponding futex_wake code around it. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Mel Gorman <mgorman@suse.de> Link: http://lkml.kernel.org/r/1429894848.10273.44.camel@stgolabs.net Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-09-29perf bench futex: Sanitize -q option in requeueDavidlohr Bueso1-1/+3
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>
2014-09-29perf bench futex: Support operations for shared futexesDavidlohr Bueso1-9/+15
Unlike futex-hash, requeuing and wakeup benchmarks do not support shared futexes, limiting the usefulness of the programs. Correct this, and allow using the local -S parameter. The default remains using private futexes. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Davidlohr Bueso <dbueso@suse.de> Link: http://lkml.kernel.org/r/1412008868-22328-1-git-send-email-dave@stgolabs.net Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-06-19perf bench futex: Use global --repeat optionDavidlohr Bueso1-9/+1
This option is available through perf-bench, use it instead and free the local option. Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> Cc: Jiri Olsa <jolsa@kernel.org> Link: http://lkml.kernel.org/r/1402942467-10671-6-git-send-email-davidlohr@hp.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-03-14perf bench: Add futex-requeue microbenchmarkDavidlohr Bueso1-0/+211
Block a bunch of threads on a futex and requeue them on another, N at a time. This program is particularly useful to measure the latency of nthread requeues without waking up any tasks -- thus mimicking a regular futex_wait. An example run: $ perf bench futex requeue -r 100 -t 64 Run summary [PID 151011]: Requeuing 64 threads (from 0x7d15c4 to 0x7d15c8), 1 at a time. [Run 1]: Requeued 64 of 64 threads in 0.0400 ms [Run 2]: Requeued 64 of 64 threads in 0.0390 ms [Run 3]: Requeued 64 of 64 threads in 0.0400 ms ... [Run 100]: Requeued 64 of 64 threads in 0.0390 ms Requeued 64 of 64 threads in 0.0399 ms (+-0.37%) Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Acked-by: Darren Hart <dvhart@linux.intel.com> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Darren Hart <dvhart@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Low <jason.low2@hp.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <Waiman.Long@hp.com> Link: http://lkml.kernel.org/r/1387081917-9102-4-git-send-email-davidlohr@hp.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>