From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C0753C432C0 for ; Thu, 28 Nov 2019 12:39:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A07E42084D for ; Thu, 28 Nov 2019 12:39:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726565AbfK1Mj3 (ORCPT ); Thu, 28 Nov 2019 07:39:29 -0500 Received: from mx2.suse.de ([195.135.220.15]:45470 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726227AbfK1Mj2 (ORCPT ); Thu, 28 Nov 2019 07:39:28 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8169FABF4; Thu, 28 Nov 2019 12:39:26 +0000 (UTC) Date: Thu, 28 Nov 2019 13:39:24 +0100 From: Michal =?iso-8859-1?Q?Koutn=FD?= To: =?utf-8?B?546L6LSH?= Cc: Mel Gorman , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Luis Chamberlain , Kees Cook , Iurii Zaikin , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, "Paul E. McKenney" Subject: Re: [PATCH v2 1/3] sched/numa: advanced per-cgroup numa statistic Message-ID: <20191128123924.GD831@blackbody.suse.cz> References: <743eecad-9556-a241-546b-c8a66339840e@linux.alibaba.com> <207ef46c-672c-27c8-2012-735bd692a6de@linux.alibaba.com> <9354ffe8-81ba-9e76-e0b3-222bc942b3fc@linux.alibaba.com> <20191127101932.GN28938@suse.de> <3ff78d18-fa29-13f3-81e5-a05537a2e344@linux.alibaba.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="OaZoDhBhXzo6bW1J" Content-Disposition: inline In-Reply-To: <3ff78d18-fa29-13f3-81e5-a05537a2e344@linux.alibaba.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org --OaZoDhBhXzo6bW1J Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hello. My primary concern is still the measuring of per-NUMA node execution time. First, I think exposing the aggregated data into the numa_stat file is loss of information. The data are collected per-CPU and then summed over NUMA nodes -- this could be easily done by the userspace consumer of the data, keeping the per-CPU data available. Second, comparing with the cpuacct implementation, yours has only jiffy granularity (I may have overlooked something or I miss some context, then it's a non-concern). IOW, to me it sounds like duplicating cpuacct job and if that is deemed useful for cgroup v2, I think it should be done (only once) and at proper place (i.e. how cputime is measured in the default hierarchy). The previous two are design/theoretical remarks, however, your patch misses measuring of other than fair_sched_class policy tasks. Is that intentional? My last two comments are to locality measurement but are based on no experience or specific knowledge. The seven percentile groups seem quite arbitrary to me, I find it strange that the ratio of cache-line size and u64 leaks and is fixed in the generally visible file. Wouldn't such a form be better hidden under a _DEBUG config option? On Thu, Nov 28, 2019 at 10:09:13AM +0800, =E7=8E=8B=E8=B4=87 wrote: > Consider it as load_1/5/15 which not accurate but tell the trend of system I understood your patchset provides cumulative data over time, i.e. if a user wants to see an immediate trend, they have to calculate differences. Have I overlooked some back-off or regular zeroing? Michal --OaZoDhBhXzo6bW1J Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEEoQaUCWq8F2Id1tNia1+riC5qSgFAl3fv/YACgkQia1+riC5 qSgj9Q/+I2TOZZ+nPAuxua7tVrpl21jtNgWwoNQOZpN84ZSwGCk2tlwRdhnu/SMz pUGu1JJqcIQcuYBob+tHafkvyMQ0xBvAzpAQWbc4rGNJNSiIrqWzl+Kn/E82Wqz+ Jxbwude/xvITRvac3VjZbVkr0Ml49sJ/hxXXJfdSrKdWJYo2Rt1WTDjrU7dWQ027 FVuJKmrlzn20y53MBgNo7WZ5NV5IP/GpXUp1GHq42taJT79McycuxDs7JSt55cq4 BrYiLWL+vrFG3fkPt8InEnR89+cZY7ZDk+x5kxwtljyPjGHdZDGIqyiuZSH/S2XX 4uZQtk2hXVAyhixUbu5ktRqg0FfmwXOz3BAltsm2iJQETl7JjCILTLVTu3OJYHtB FONUEwTZAiOEFFIZdmhGAdJRlqNaEi0iMWS7qBfKJTKbG7ZA4R1UdfjhxFgOH+Ag dyr19qa//q+FT9yp3Lxwk/jbkvEcGZvom+AY1A6AyirlhvdmcfbDDqLK1wgstWaM N0Nyv10sbNsYMHW8h72d9rcgatD+O0hLPYbOtSSntlo4nlh2FaD6/TA1ml7qXNDo QtPyfalbhNYru9zrjkcv9PQYXNj7vCrLNkXtJ6ksuFRfyz4LgAtZiX5EVyBf9FGb YCENs8Yw25crUt6H1vdfMZCE6HigJbJKgn4X+1N3bCJ0uwLPci8= =YWb4 -----END PGP SIGNATURE----- --OaZoDhBhXzo6bW1J--