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References: <20231017202342.1353124-1-namhyung@kernel.org> <ZTLjx3A8LBQMYWHJ@kernel.org>
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From:   Namhyung Kim <namhyung@kernel.org>
Date:   Fri, 20 Oct 2023 14:13:50 -0700
Message-ID: <CAM9d7cjoStnwi+UbruGKxYbmKnD0+TU4u5suacQFLt6sb5tf=g@mail.gmail.com>
Subject: Re: [PATCH v4] perf bench sched pipe: Add -G/--cgroups option
To:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Ingo Molnar <mingo@kernel.org>
Cc:     Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-perf-users@vger.kernel.org
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On Fri, Oct 20, 2023 at 1:32 PM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> Em Tue, Oct 17, 2023 at 01:23:42PM -0700, Namhyung Kim escreveu:
> > The -G/--cgroups option is to put sender and receiver in different
> > cgroups in order to measure cgroup context switch overheads.
> <SNIP>
> >   > taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB > /dev/null
>
> >    Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB':
> >
> >               20,001      context-switches
> >               20,001      cgroup-switches
>
> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Thanks a lot Arnaldo!

Ingo, can I keep you Acked-by here? (forgot to add in v4, sorry!)

Thanks,
Namhyung

>
> [root@five ~]# perf stat -e context-switches,cgroup-switches taskset -c 0 perf bench sched pipe -l 10000
> # Running 'sched/pipe' benchmark:
> # Executed 10000 pipe operations between two processes
>
>      Total time: 0.063 [sec]
>
>        6.367500 usecs/op
>          157047 ops/sec
>
>  Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 10000':
>
>             20,004      context-switches
>                  4      cgroup-switches
>
>        0.084191842 seconds time elapsed
>
>        0.008332000 seconds user
>        0.067193000 seconds sys
>
>
> [root@five ~]# perf stat -e context-switches,cgroup-switches taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB
> # Running 'sched/pipe' benchmark:
> no access to cgroup /sys/fs/cgroup/BBB
> Failed to open cgroup file in BBB
>  Hint: create the cgroup first, like 'mkdir /sys/fs/cgroup/BBB'
> no access to cgroup /sys/fs/cgroup/AAA
> Failed to open cgroup file in AAA
>  Hint: create the cgroup first, like 'mkdir /sys/fs/cgroup/AAA'
>
>  Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB':
>
>                  2      context-switches
>                  1      cgroup-switches
>
>        0.010356533 seconds time elapsed
>
>        0.003209000 seconds user
>        0.007122000 seconds sys
>
>
> [root@five ~]# vim /tmp/bla
> [root@five ~]#
> [root@five ~]# mkdir /sys/fs/cgroup/BBB /sys/fs/cgroup/AAA
> [root@five ~]# perf stat -e context-switches,cgroup-switches taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB
> # Running 'sched/pipe' benchmark:
> # Executed 10000 pipe operations between two processes
>
>      Total time: 0.079 [sec]
>
>        7.987800 usecs/op
>          125190 ops/sec
>
>  Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB':
>
>             20,008      context-switches
>             20,007      cgroup-switches
>
>        0.089361029 seconds time elapsed
>
>        0.009004000 seconds user
>        0.065376000 seconds sys
>
>
> [root@five ~]#