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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 132DEC76196 for ; Tue, 28 Mar 2023 12:48:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232974AbjC1MsD (ORCPT ); Tue, 28 Mar 2023 08:48:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40882 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232502AbjC1Mrw (ORCPT ); Tue, 28 Mar 2023 08:47:52 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 702019ED1; Tue, 28 Mar 2023 05:47:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 54067B81CA2; Tue, 28 Mar 2023 12:46:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96F6CC433D2; Tue, 28 Mar 2023 12:46:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680007584; bh=GuCEmU1vSIWBl2zkABCTKL9E15vkPCNZhOh2vievgec=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MLZQAhjEw/Z+YtN90zEUp/GOL5ddjdyq9ks67DWjGNEfgCNxc1UzWWn/JrsPQYqGG uIs2TtoZl/iy7kBvzUWxo1kapegOOcao12q4YzseMFfxhzbTxwC0BDjZDZ7ux0shi9 gV1EoaFnoAX54JWEobieF77z/adDkXxAF1If/nvY= Date: Tue, 28 Mar 2023 14:46:21 +0200 From: Greg KH To: Zhang Qiao Cc: stable@vger.kernel.org, Sasha Levin , stable-commits@vger.kernel.org, Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider Subject: Re: Patch "sched/fair: sanitize vruntime of entity being placed" has been added to the 4.14-stable tree Message-ID: References: <20230305040248.1787312-1-sashal@kernel.org> <1f8388a8-39cf-080c-4a6d-36b3059544a5@huawei.com> <899c8be7-fe1a-7dd2-c174-6a8b9934ba39@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <899c8be7-fe1a-7dd2-c174-6a8b9934ba39@huawei.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Mar 28, 2023 at 05:02:21PM +0800, Zhang Qiao wrote: > > > 在 2023/3/7 23:23, Greg KH 写道: > > On Mon, Mar 06, 2023 at 06:51:15PM +0800, Zhang Qiao wrote: > >> > >> > >> 在 2023/3/6 18:05, Greg KH 写道: > >>> On Mon, Mar 06, 2023 at 05:28:41PM +0800, Zhang Qiao wrote: > >>>> > >>>> > >>>> 在 2023/3/6 17:19, Greg KH 写道: > >>>>> On Mon, Mar 06, 2023 at 04:31:57PM +0800, Zhang Qiao wrote: > >>>>>> > >>>>>> > >>>>>> 在 2023/3/5 12:02, Sasha Levin 写道: > >>>>>>> This is a note to let you know that I've just added the patch titled > >>>>>>> > >>>>>>> sched/fair: sanitize vruntime of entity being placed > >>>>>>> > >>>>>>> to the 4.14-stable tree which can be found at: > >>>>>>> http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary > >>>>>>> > >>>>>>> The filename of the patch is: > >>>>>>> sched-fair-sanitize-vruntime-of-entity-being-placed.patch > >>>>>>> and it can be found in the queue-4.14 subdirectory. > >>>>>>> > >>>>>>> If you, or anyone else, feels it should not be added to the stable tree, > >>>>>>> please let know about it. > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>> commit 38247e1de3305a6ef644404ac818bc6129440eae > >>>>>> > >>>>>> Hi, > >>>>>> This patch has significant impact on the hackbench.throughput [1]. > >>>>>> Please don't backport this patch. > >>>>>> > >>>>>> [1] https://lore.kernel.org/lkml/202302211553.9738f304-yujie.liu@intel.com/T/#u > >>>>> > >>>>> This link says it made hackbench.throughput faster, not slower, so why > >>>>> would we NOT want it? > >>>> > >>>> Please see this section. In some cases, this patch reset task's vruntime by mistake and > >>>> will lead to wrong results. > >>>> > >>>> > >>>> On Tue, Feb 21, 2023 at 03:34:16PM +0800, kernel test robot wrote: > >>>>> > >>>>> FYI, In addition to that, the commit also has significant impact on the following tests: > >>>>> > >>>>> +------------------+--------------------------------------------------+ > >>>>> | testcase: change | hackbench: hackbench.throughput -8.1% regression | > >>>>> | test machine | 104 threads 2 sockets (Skylake) with 192G memory | > >>>>> | test parameters | cpufreq_governor=performance | > >>>>> | | ipc=socket | > >>>>> | | iterations=4 | > >>>>> | | mode=process | > >>>>> | | nr_threads=100% | > >>>>> +------------------+--------------------------------------------------+ > >>>>> > >>>>> Details are as below: > >>> > >>> So one benchmark did better, by a lot, and one did less, by a little? > >>> Which one matters "more"> > >>> > >>> So Linus's tree now has a regression? Or not? I'm confused. We are > >> > >> Yes, Linus's tree also has a regression, and i have sent a patch[1] for fix this regression. > >> > >> > >> [1]: https://lore.kernel.org/lkml/79850642-ebac-5c23-d32d-b28737dcb91e@huawei.com/ > >> > >> thanks. > >> Zhang qiao. > > > > Ok, I've dropped this from all stable queues now. Please let us know > > when we can pick it up again and what the fixup commit id in Linus's > > tree is when it lands there. > > Hi, > > The fixup patch has been merged into Linus's tree, its commit id is: > a53ce18cacb477dd0513c607f187d16f0fa96f71 ("sched/fair: Sanitize vruntime of entity being migrated") Wonderful, I have queued both of these up now, thank you for letting me know. greg k-h