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 7DB8EC77B75 for ; Tue, 18 Apr 2023 14:32:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231673AbjDROc2 (ORCPT ); Tue, 18 Apr 2023 10:32:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231384AbjDROcZ (ORCPT ); Tue, 18 Apr 2023 10:32:25 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4504413F8F for ; Tue, 18 Apr 2023 07:31:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681828297; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Obc8o7+Jc2/xwzIMnjHntcd92yYzpwyuQHbYi3m2V4g=; b=gBE/jNRMTBVX7TaIAmVeObUB6kaHr1z/bvgPE6Tq1ttFup8l5ZpJNVogf3dI/dafeQ9oY5 jZ9sJV5F5w2OXBdtxjaS00FA55+BLOqgPdsaqIyhWVjs+7WUibXQbO0YYLpdtNPdOADPS2 Njrt04Es7F+zotx7qwJ0VjmjbNHS8uE= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-118-JXl42fi3NSi0HJY4UsjPfQ-1; Tue, 18 Apr 2023 10:31:34 -0400 X-MC-Unique: JXl42fi3NSi0HJY4UsjPfQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5E43D88B7AA; Tue, 18 Apr 2023 14:31:29 +0000 (UTC) Received: from [10.22.34.98] (unknown [10.22.34.98]) by smtp.corp.redhat.com (Postfix) with ESMTP id 44BD540C6E70; Tue, 18 Apr 2023 14:31:27 +0000 (UTC) Message-ID: Date: Tue, 18 Apr 2023 10:31:27 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: [PATCH 0/6] sched/deadline: cpuset: Rework DEADLINE bandwidth restoration Content-Language: en-US To: Qais Yousef , Juri Lelli Cc: Peter Zijlstra , Ingo Molnar , Tejun Heo , Zefan Li , Johannes Weiner , Hao Luo , Dietmar Eggemann , Steven Rostedt , linux-kernel@vger.kernel.org, luca.abeni@santannapisa.it, claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it, bristot@redhat.com, mathieu.poirier@linaro.org, cgroups@vger.kernel.org, Vincent Guittot , Wei Wang , Rick Yiu , Quentin Perret , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Sudeep Holla References: <20230329125558.255239-1-juri.lelli@redhat.com> <20230418141127.zbvsf7lwk27zvipt@airbuntu> From: Waiman Long In-Reply-To: <20230418141127.zbvsf7lwk27zvipt@airbuntu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/18/23 10:11, Qais Yousef wrote: > On 03/29/23 14:55, Juri Lelli wrote: >> Qais reported [1] that iterating over all tasks when rebuilding root >> domains for finding out which ones are DEADLINE and need their bandwidth >> correctly restored on such root domains can be a costly operation (10+ >> ms delays on suspend-resume). He proposed we skip rebuilding root >> domains for certain operations, but that approach seemed arch specific >> and possibly prone to errors, as paths that ultimately trigger a rebuild >> might be quite convoluted (thanks Qais for spending time on this!). >> >> To fix the problem >> >> 01/06 - Rename functions deadline with DEADLINE accounting (cleanup >> suggested by Qais) - no functional change >> 02/06 - Bring back cpuset_mutex (so that we have write access to cpusets >> from scheduler operations - and we also fix some problems >> associated to percpu_cpuset_rwsem) >> 03/06 - Keep track of the number of DEADLINE tasks belonging to each cpuset >> 04/06 - Create DL BW alloc, free & check overflow interface for bulk >> bandwidth allocation/removal - no functional change >> 05/06 - Fix bandwidth allocation handling for cgroup operation >> involving multiple tasks >> 06/06 - Use this information to only perform the costly iteration if >> DEADLINE tasks are actually present in the cpuset for which a >> corresponding root domain is being rebuilt >> >> With respect to the RFC posting [2] >> >> 1 - rename DEADLINE bandwidth accounting functions - Qais >> 2 - call inc/dec_dl_tasks_cs from switched_{to,from}_dl - Qais >> 3 - fix DEADLINE bandwidth allocation with multiple tasks - Waiman, >> contributed by Dietmar >> >> This set is also available from >> >> https://github.com/jlelli/linux.git deadline/rework-cpusets > Is this just waiting to be picked up or still there's something to be addressed > still? There are some changes to cpuset code recently and so I believe that this patch series may need to be refreshed to reconcile the changes. Thanks, Longman