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>
There are a number of benchmarks that do single runs and as a result
does not really help users gain a general idea of how the workload
performs. So the user must either manually do multiple runs or just use
single bogus results.
This option will enable users to specify the amount of runs (arbitrarily
defaulted to 10, to use the existing benchmarks default) through the
'--repeat' option. Add it to perf-bench instead of implementing it
always in each specific benchmark.
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/1402942467-10671-2-git-send-email-davidlohr@hp.com
[ Kept the existing default of 10, changing it to something else should
be done on separate patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As Namhyung Kim pointed, there are confused namings and descriptions of words
"cycle" and "clock" in mem-memset.c and mem-memcpy.c.
With the option "-c" (or "--clock", now renamed as "--cycle"), mem subsystem
measures cost of memset() and memcpy() with cpu-cycles event.
But current mem subsystem source code contains lots of confused variable
namings and descriptions with "clock" (e.g. the variable use_clock). This is a
very bad style because there is another software event named "cpu-clock". This
patch replaces wrong usage of "clock" to "cycle".
v2: modified Documentation/perf-bench.txt for the descriptions of
--cycle option
Signed-off-by: Hitoshi Mitake <h.mitake@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1341236777-18457-1-git-send-email-h.mitake@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The current perf-bench documentation has a couple of typos and even
lacks entire description of mem subsystem. Fix it.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1340172486-17805-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Correct typos in perf bench & perf sched help text.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20100331113100.cc898487.randy.dunlap@oracle.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
This patch adds new document about perf-bench.
Man page and html will be provided for user.
Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1257853855-28934-3-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
