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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 9ABBBC433E2 for ; Wed, 9 Sep 2020 22:39:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 440B921D7E for ; Wed, 9 Sep 2020 22:39:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599691142; bh=yat5qEF1R5Wi8ynqYlJsDRaKkP24UNOVO0pWcjtQ5r4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=iv88u6SIELIgoHT8MTD9VjiBkIzEwmqtqvazsn4BWjb5Aj0JjLn3qh4XzA5ACeW8/ AGUpiS/yu7wXax9GQWz3tTIq2vuzxWQIAeQsEgfvH8s4cOD1W/5/sIDkGSwkPRIRfI KzaM2MKWOd9wi0h/c0TgYVRlIxnh9b/1Y0Q5r1T8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728350AbgIIWjA (ORCPT ); Wed, 9 Sep 2020 18:39:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:51518 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726489AbgIIWi7 (ORCPT ); Wed, 9 Sep 2020 18:38:59 -0400 Received: from localhost (lfbn-ncy-1-588-162.w81-51.abo.wanadoo.fr [81.51.203.162]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6E8CA20C09; Wed, 9 Sep 2020 22:38:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599691138; bh=yat5qEF1R5Wi8ynqYlJsDRaKkP24UNOVO0pWcjtQ5r4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fOSS7FUOCNOtmolfkDcK2XSQIEP4VvLYrcUy1ovKzcVirOB3tnXzqWxykFDJ2K06/ QKrAfqs7/Dy2feGXP3UHSZ9Q1ZP4xT38osGtyASaXYLOypXXL+wkmV4Tpp3P4a8xkr 43HJgvX7QTLQ3HZVPbxT/qVbShKQfTl8frzLqcRA= Date: Thu, 10 Sep 2020 00:38:56 +0200 From: Frederic Weisbecker To: Marcelo Tosatti Cc: Phil Auld , Peter Zijlstra , Thomas Gleixner , "Paul E. McKenney" , Joel Fernandes , linux-kernel@vger.kernel.org Subject: Re: Requirements to control kernel isolation/nohz_full at runtime Message-ID: <20200909223856.GB20541@lenoir> References: <20200901104640.GA13814@lenoir> <20200903182359.GA1016174@fuller.cnet> <20200903183015.GA1027417@fuller.cnet> <20200903183636.GB99697@lorien.usersys.redhat.com> <20200903185200.GA1029791@fuller.cnet> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200903185200.GA1029791@fuller.cnet> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 03, 2020 at 03:52:00PM -0300, Marcelo Tosatti wrote: > On Thu, Sep 03, 2020 at 02:36:36PM -0400, Phil Auld wrote: > > exclusive cpusets is used now to control scheduler load balancing on > > a group of cpus. It seems to me that this is the same idea and is part > > of the isolation concept. Having a toggle for each subsystem/feature in > > cpusets could provide the needed userspace api. > > > > Under the covers it might be implemented as twiddling various cpumasks. > > > > We need to be shifting to managing load balancing with cpusets anyway. > > OK, adding a new file per isolation feature: > > - cpuset.isolation_nohz_full > - cpuset.isolation_kthread > - cpuset.isolation_time > > With a bool value per file, is an option. Exactly. I would merge kthread/timers/workqueue into cpuset.isolation.unbound though. Unless anyone may need more granularity there?