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 F16DCC7EE21 for ; Thu, 4 May 2023 08:18:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229872AbjEDISf (ORCPT ); Thu, 4 May 2023 04:18:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60720 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230183AbjEDIRy (ORCPT ); Thu, 4 May 2023 04:17:54 -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 6DD395BA1 for ; Thu, 4 May 2023 01:13:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1683187987; 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: in-reply-to:in-reply-to:references:references; bh=Rvq9QYdFcVHzrD8NG0o1jSPMkcXmSSUXCp6nCK/Vwpg=; b=F1pCiity+N7IBL9c54xby+07f4dL9CixkQOb80cYFEV8KD9V7ECqlGjSYtrvsfQUTEXKG0 fRswP9RFlSTm+VjETyEvgho/SUXV2BYSK3BtakhP3QroSg0JJ6Xt0zJgIriScrNgU3ptRH N6a61WwCbHn6tJpYXDkVJl0Pez2RkC8= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-410-ogwnqM5RPZqxAbGV12aoZQ-1; Thu, 04 May 2023 04:13:06 -0400 X-MC-Unique: ogwnqM5RPZqxAbGV12aoZQ-1 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-3f173bd0fc9so969335e9.3 for ; Thu, 04 May 2023 01:13:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683187985; x=1685779985; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Rvq9QYdFcVHzrD8NG0o1jSPMkcXmSSUXCp6nCK/Vwpg=; b=WxqXohoZt7/IlG++P05ZE0M9LO9iOlK/DYbKRUW3Z5foJetK7Pc+6TLP0QKImJrNX2 kPi6kVa3l2B620k0fUyTj8eq/L2jzZRoTfkjy1rlfVHo+5pG4Ik3OPbI5jBKuia4/UGU U6rilca8A9zs7eGU8toQJoGXdBn40gq78UzSizlcp53qR+klMIk4kBBAXuT0x7qQZt1c cS/QI5GrwS7yC40s8Ji3o2INkazRNKcBsiR/u+ynQd2kuOdRw7qCvxfa8nxLnP+W0YDK uegp4e0J8pYillZ29uf/SSDWZNVOsGZ+m2Khd+vafTcss8Xtlx39JuNlpN5eVxokwKaB QZNQ== X-Gm-Message-State: AC+VfDwKWPzLI7BLpWO8OgXWt5v4lARwu+YIfO4Dh4653yKrUt6VDkj3 C/ECyv48INwp7lcVzJPkBDcSXZjvsYZHmu6Vity6WiMdVGuuYbY2qkklXFKCc4YPMgR6hTYLKrv guhDRqR/vUi1LZ9fcGDhpjvJ1 X-Received: by 2002:a05:600c:24a:b0:3f2:51e7:f1f4 with SMTP id 10-20020a05600c024a00b003f251e7f1f4mr16934218wmj.10.1683187985569; Thu, 04 May 2023 01:13:05 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ4hVkeTRIDeTn1+y9PxDztu4Y6xMSwemGP+0X5YDwN5BdbQORRsgFb4petN+HtAjvh7m9g+7A== X-Received: by 2002:a05:600c:24a:b0:3f2:51e7:f1f4 with SMTP id 10-20020a05600c024a00b003f251e7f1f4mr16934181wmj.10.1683187985261; Thu, 04 May 2023 01:13:05 -0700 (PDT) Received: from localhost.localdomain ([2a02:b121:8011:79a:2d6b:5410:3927:2f38]) by smtp.gmail.com with ESMTPSA id u19-20020a05600c00d300b003f19bca8f03sm4065842wmm.43.2023.05.04.01.13.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 May 2023 01:13:04 -0700 (PDT) Date: Thu, 4 May 2023 10:13:00 +0200 From: Juri Lelli To: Peter Zijlstra Cc: Ingo Molnar , Qais Yousef , Waiman Long , 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 Subject: Re: [PATCH v2 2/6] sched/cpuset: Bring back cpuset_mutex Message-ID: References: <20230503072228.115707-1-juri.lelli@redhat.com> <20230503072228.115707-3-juri.lelli@redhat.com> <20230504062105.GD1734100@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230504062105.GD1734100@hirez.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/05/23 08:21, Peter Zijlstra wrote: > On Wed, May 03, 2023 at 09:22:24AM +0200, Juri Lelli wrote: > > Turns out percpu_cpuset_rwsem - commit 1243dc518c9d ("cgroup/cpuset: > > Convert cpuset_mutex to percpu_rwsem") - wasn't such a brilliant idea, > > as it has been reported to cause slowdowns in workloads that need to > > change cpuset configuration frequently and it is also not implementing > > priority inheritance (which causes troubles with realtime workloads). > > What were they doing ? Dynamically adjusting the DL parameters? > Yes, calling sched_setattr to adjust params and/or add/remove DL reservations.