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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 6B3D0C43331 for ; Thu, 26 Mar 2020 19:49:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 40B59206E6 for ; Thu, 26 Mar 2020 19:49:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585252140; bh=Mh+S9GbQhw3wCPkX9gcjVXdDLi+k8s2FZAJmKj4SQKQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=akSrMCkoVvfqQ0PT3muS4CmyxkMrOoRoFN1neDoWmXFsb/viKeA/70RD6bMwqCpkz u2crwZVbxgdi26Obq0CL+j7cKWAK1m+8bPS/FJi7xkuN+Tn2dpyYw0TiV+FH4AofAb 2U19beNpTuWbEQ+WXcx3Q7kVFz8NW9Y/CFtCSp1U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728642AbgCZTs7 (ORCPT ); Thu, 26 Mar 2020 15:48:59 -0400 Received: from mail-qt1-f195.google.com ([209.85.160.195]:33202 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726067AbgCZTs6 (ORCPT ); Thu, 26 Mar 2020 15:48:58 -0400 Received: by mail-qt1-f195.google.com with SMTP id c14so6608769qtp.0; Thu, 26 Mar 2020 12:48:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=+X43fOowivo9wQhliFx6lnhtIaMEbCHpeVUMSBZZuGY=; b=U5JDgEKNA0GkBeHvV5CHdgdArh42FYVrmzkogGBIyPh3UbwY/HtRPl1L7OI8kSvTuM t7BJG7ezUxnmgRFbliiaIwK8OBPkiXIeGrhetTsK6rDsWt1lNTKwuMPWLqOYF0Uz07uP vlAyx6tjVavmsfFsclBaBM5kI1FLo9fg+4Ct2XX22fBdqTWnySs24i1kyUSGY1vHhgPy CuU82/h7zfoXRaJJcIxxSNIjvjQrS8IIf64WfaRfpBpfzEocyTurwPs9dmGXh/+Q/esb pdpiaqT4PIpE6gDZyhqhdIScxy7PlNi43u4b6oe1NowK41XpBBOw6RXKLF4zN+sjinb5 JVnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=+X43fOowivo9wQhliFx6lnhtIaMEbCHpeVUMSBZZuGY=; b=gpHMmgwjXTLKJQifPSzZLLaN3v+PGWZSCJ80XSVyvmKCPJra3h5OQ0fDUV0ImaYnn3 2Gq3WCxKiveUTZDKIjK2KsQ3FlF5yq1usYD7kYFkbeYgMETG5Zxp6eiIVnXml6ix55sv 2+Tp4LEwQbwoiqnKbsAB296CkuLZgwgiKHYbVOnESrp4AeyvnpxVqwRmSllZHRtEWuG8 Ro7d78oOf4gMWrjKF7FzVCtZCUg2HiewgV0euuneNznaoKn2C39u/cbwmOvb/rVA+fae B2STsO+8kGrfNUNhLh5ZtRXZ1F+p0lTSdU62ADb0VFxNvmNLkB83swA+dM8IKP29neQd GrYQ== X-Gm-Message-State: ANhLgQ3Z5kYKtiCZEuINIodqUmW7P96jddmWcW9U+bCjSuSGXxYW+SWK KOaDYfLnkWcMLhlwBG7SIP5RPpTl2yM= X-Google-Smtp-Source: ADFU+vtLFlzARKEMRWc1YGd7T4n7YiyfdU1NRA6ydWosFisgJpC626glGMvBSi56eVhlehZTCUKjjA== X-Received: by 2002:ac8:366d:: with SMTP id n42mr10293278qtb.180.1585252137334; Thu, 26 Mar 2020 12:48:57 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::d3b8]) by smtp.gmail.com with ESMTPSA id 10sm1707115qtt.54.2020.03.26.12.48.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Mar 2020 12:48:56 -0700 (PDT) Date: Thu, 26 Mar 2020 15:48:55 -0400 From: Tejun Heo To: Joel Fernandes Cc: linux-kernel@vger.kernel.org, Dmitry Shmidt , Amit Pundir , kernel-team@android.com, jsbarnes@google.com, sonnyrao@google.com, vpillai@digitalocean.com, peterz@infradead.org, Guenter Roeck , Waiman Long , Greg Kerr , cgroups@vger.kernel.org, Johannes Weiner , Li Zefan Subject: Re: [PATCH RFC] cpuset: Make cpusets get restored on hotplug Message-ID: <20200326194855.GP162390@mtj.duckdns.org> References: <20200326191623.129285-1-joel@joelfernandes.org> <20200326192035.GO162390@mtj.duckdns.org> <20200326194448.GA133524@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200326194448.GA133524@google.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 26, 2020 at 03:44:48PM -0400, Joel Fernandes wrote: > It is not really that big a change. Please go over the patch, we are not > changing anything with how ->cpus_allowed works and interacts with the rest > of the system and the scheduler. We have just introduced a new mask to keep > track of which CPUs were requested without them being affected by hotplug. On > CPU onlining, we restore the state of ->cpus_allowed as not be affected by > hotplug. It's not the code. It's the behavior. I'm not flipping the behavior for the existing cgroup1 users underneath them at this point. As-is, it's a hard nack. If you really really really want it, put it behind a mount option. -- tejun