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From:   Namhyung Kim <namhyung@kernel.org>
Date:   Wed, 15 Nov 2023 07:48:33 -0800
Message-ID: <CAM9d7cgdUJytP31y90c5AuQAmR6FgkBWjj4brVjH8Pg+d00O+Q@mail.gmail.com>
Subject: Re: [Regression or Fix]perf: profiling stats sigificantly changed for
 aio_write/read(ext4) between 6.7.0-rc1 and 6.6.0
To:     David Wang <00107082@163.com>
Cc:     Peter Zijlstra <peterz@infradead.org>, mingo@redhat.com,
        acme@kernel.org, mark.rutland@arm.com,
        alexander.shishkin@linux.intel.com, jolsa@kernel.org,
        irogers@google.com, adrian.hunter@intel.com,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
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On Wed, Nov 15, 2023 at 3:00 AM David Wang <00107082@163.com> wrote:
>
>
>
> At 2023-11-15 18:32:41, "Peter Zijlstra" <peterz@infradead.org> wrote:
> >
> >Namhyung, could you please take a look, you know how to operate this
> >cgroup stuff.
> >
>
> More information,  I run the profiling with 8cpu machine on a SSD with ext4 filesystem :
>
> # mkdir /sys/fs/cgroup/mytest
> # echo $$ > /sys/fs/cgroup/mytest/cgroup.procs
> ## Start profiling targeting cgroup /sys/fs/cgroup/mytest   on another terminal
> # fio --randrepeat=1 --ioengine=libaio --direct=1 --name=test  --bs=4k --iodepth=64 --size=1G --readwrite=randrw  --runtime=600 --numjobs=4 --time_based=1
>
> I got a feeling that f06cc667f7990 would decrease total samples by 10%~20% when profiling IO benchmark within cgroup.

Oh sorry, I missed this message.  Can you please share the
command line and the output?

Thanks,
Namhyung