From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A5B12182AC for ; Wed, 15 Nov 2023 16:26:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from mail-pg1-f173.google.com (mail-pg1-f173.google.com [209.85.215.173]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 85A3AAB; Wed, 15 Nov 2023 08:26:18 -0800 (PST) Received: by mail-pg1-f173.google.com with SMTP id 41be03b00d2f7-5bdbe2de25fso5441242a12.3; Wed, 15 Nov 2023 08:26:18 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700065578; x=1700670378; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=7XbGNtZYQzrg+K/86U5tkkq4BRBUIpICB/C0IOeiM6Q=; b=KLHUmA4/es8Rcr3QDHXNmJv6QrcaZJ6zXcIjGA37Vc8IBpFxjc4cm4LImrxbzwKuam 4QDmDcQQirFOT+uEVJWEM9w0aTfW5ZFdqRbKFG4IOsDgNK547IhUWhyY5JZ5U4Xytqv4 zvsQsbRoR1eAl1rTHgxS5kqWzbnldHIoC2+rYGqOQ5pv9C1jP5hqnpmaSVA18BQlwxsI wnJMF60cuoIaEogI7ALYTO+HC3igpkw4GAVNcn5RUMqD+FCEPtjnymn2ZqBZR6s0Tdol BoDgmuPGupBzVBvsZhbx+tyi/gnct9q8tFiW6QzNdJboJ1eBWSeWgHTSTbVPZoJfoZWf mMgA== X-Gm-Message-State: AOJu0YwuXTOOK0har0fLWXRdvvMIzWNXl2l2K4KD5I4pYXUithxGU9Mr Z/aTJ+/dLaGlAG8VOUCGlwN8stRBmo6eG/K8fDY= X-Google-Smtp-Source: AGHT+IF5g1wRBbrnBPwjzq/pQzH6gj1NY7XTcsRAlsqoLpnDnPN1IgoVgSxKIo3KkCbBz+xSQQapxKxtokP116cJH24= X-Received: by 2002:a17:90b:2789:b0:283:2932:e912 with SMTP id pw9-20020a17090b278900b002832932e912mr14944255pjb.28.1700065577790; Wed, 15 Nov 2023 08:26:17 -0800 (PST) Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <449fb8d2.27fb.18bcc190021.Coremail.00107082@163.com> <76d75357.6ab6.18bce6b7d5b.Coremail.00107082@163.com> <20231115103241.GD3818@noisy.programming.kicks-ass.net> <407a06f8.632a.18bd2a2ece1.Coremail.00107082@163.com> <1a1338d0.6b3a.18bd3c09056.Coremail.00107082@163.com> In-Reply-To: <1a1338d0.6b3a.18bd3c09056.Coremail.00107082@163.com> From: Namhyung Kim Date: Wed, 15 Nov 2023 08:26:06 -0800 Message-ID: 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 , 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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, Nov 15, 2023 at 8:12=E2=80=AFAM David Wang <00107082@163.com> wrote= : > > > =E5=9C=A8 2023-11-15 23:48:33=EF=BC=8C"Namhyung Kim" =E5=86=99=E9=81=93=EF=BC=9A > >On Wed, Nov 15, 2023 at 3:00=E2=80=AFAM David Wang <00107082@163.com> wr= ote: > >> > >> > >> > >> At 2023-11-15 18:32:41, "Peter Zijlstra" 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=3D1 --ioengine=3Dlibaio --direct=3D1 --name=3Dtest = --bs=3D4k --iodepth=3D64 --size=3D1G --readwrite=3Drandrw --runtime=3D600= --numjobs=3D4 --time_based=3D1 > >> > >> 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? > > > I did not use perf..... This is the part where it is not quite convincin= g to report the change, I am using a profiling tool of my own as I mentione= d in the first mail..... > But I believe my profiling tools did detect some changes. Oh.. ok. You didn't use perf. Then what is your profiling tool? Where did you see the 10%~20% drop in samples? > > I am not experienced with the perf-tool at all, too complicated a tool = for me.... But I think I can try it. I feel sorry about that. In most cases, just `perf record -a` and then `perf report` would work well. :) Thanks, Namhyung