From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 61FA68495; Fri, 3 May 2024 12:59:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714741141; cv=none; b=IpZN8Qpmew+9kqu6dtCEbDf7JUg3wkgMbUq2ynwGkPrEd5PNYhuNExQ3T/GMWldw02SkObWaTbOn48UBoVQkaA94kz+kaq3fR/x6ckErpJpWcitLRIlBkUrJfbEntXgkdZq0p8j/Qvm9/a28CkqYhudw5+XFjO+brcN3As5AYpo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714741141; c=relaxed/simple; bh=Uj1cwNv+UCHnN7nqmvGy0hMOZ7WAjQ3MkfqneQLAISk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HbCrQquou5XDqY0+jKDW116rYPsHpTzjHt4pJ3eGT5iUFLxqBYTZXF0jvFPmp7oW7H28a0FqyOflZbxw8cQvREtMfGuYrUZbLGZWZwP3dPEPV8iPDNiqQxNHuQEeZmLvazR63fb0F9xhAWG3VGJgwdEbPUw3zOcaLpgrWluE0W8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Hd4GZDPD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Hd4GZDPD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF816C4AF14; Fri, 3 May 2024 12:58:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1714741141; bh=Uj1cwNv+UCHnN7nqmvGy0hMOZ7WAjQ3MkfqneQLAISk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Hd4GZDPDvredSG5fm6vJ52DUbvyC4aJvst2KyRAfrpZuByknfcR9mjqmxATyx7fsg c2FLGnPpsCc1VT3sD3B4wMOB4NKbSiJBGAooFYWR1wgHYwEcXbaTNaM6AquolWuYDY jfSZeahdvQECMks1g2M4YvD7POxUpzDWyoiL6yDzQXLdBOIOzJ8j/Dw2yXss0z5PaC XlTOsuUHWca/Jp3SR7v1vbu/mtjtI4iTLziqoOpZ+mJI2SBH+opZ3hjMpqOBWgZ4O4 4zifmO9dDEBFkMxv471+w0AVTp33PFpH55YfgiGwE6q8/kbWdFSoNd3tUyfjWXToKO uL1EqL/JYv3aA== Message-ID: Date: Fri, 3 May 2024 14:58:56 +0200 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1] cgroup/rstat: add cgroup_rstat_cpu_lock helpers and tracepoints To: Shakeel Butt Cc: Waiman Long , tj@kernel.org, hannes@cmpxchg.org, lizefan.x@bytedance.com, cgroups@vger.kernel.org, yosryahmed@google.com, netdev@vger.kernel.org, linux-mm@kvack.org, kernel-team@cloudflare.com, Arnaldo Carvalho de Melo , Sebastian Andrzej Siewior References: <171457225108.4159924.12821205549807669839.stgit@firesoul> <30d64e25-561a-41c6-ab95-f0820248e9b6@redhat.com> <4a680b80-b296-4466-895a-13239b982c85@kernel.org> <4m3x4rtztwxctwlq2pdorgbv2hblylnuc2haz7ni4ti52n57xi@utxkr5ripqp2> Content-Language: en-US From: Jesper Dangaard Brouer In-Reply-To: <4m3x4rtztwxctwlq2pdorgbv2hblylnuc2haz7ni4ti52n57xi@utxkr5ripqp2> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 02/05/2024 21.44, Shakeel Butt wrote: > On Wed, May 01, 2024 at 07:22:26PM +0200, Jesper Dangaard Brouer wrote: >> > [...] >> >> More data, the histogram of time spend under the lock have some strange >> variation issues with a group in 4ms to 65ms area. Investigating what >> can be causeing this... which next step depend in these tracepoints. >> >> @lock_cnt: 759146 >> >> @locked_ns: >> [1K, 2K) 499 | | >> [2K, 4K) 206928 >> |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| >> [4K, 8K) 147904 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | >> [8K, 16K) 64453 |@@@@@@@@@@@@@@@@ | >> [16K, 32K) 135467 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | >> [32K, 64K) 75943 |@@@@@@@@@@@@@@@@@@@ | >> [64K, 128K) 38359 |@@@@@@@@@ | >> [128K, 256K) 46597 |@@@@@@@@@@@ | >> [256K, 512K) 32466 |@@@@@@@@ | >> [512K, 1M) 3945 | | >> [1M, 2M) 642 | | >> [2M, 4M) 750 | | >> [4M, 8M) 1932 | | >> [8M, 16M) 2114 | | >> [16M, 32M) 1039 | | >> [32M, 64M) 108 | | >> > > Am I understanding correctly that 1K is 1 microsecond and 1M is 1 > millisecond? Correct. > Is it possible to further divide this table into update > side and flush side? > This is *only* flush side. You question indicate, that we are talking past each-other ;-) Measurements above is with (recently) accepted tracepoints (e.g. not the proposed tracepoints in this patch). I'm arguing with existing tracepoint that I'm seeing this data, and arguing I need per-CPU tracepoints to dig deeper into this (as proposed in this patch). The "update side" can only be measured once we apply this patch. This morning I got 6 prod machines booted with new kernels, that contain this proposed per-CPU lock tracepoint patch. And 3 of these machines have the Mutex lock change also. No data to share yet... --Jesper