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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 18501C31E49 for ; Wed, 19 Jun 2019 12:34:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E35E6208CB for ; Wed, 19 Jun 2019 12:34:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731868AbfFSMeK (ORCPT ); Wed, 19 Jun 2019 08:34:10 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:42533 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731653AbfFSMeK (ORCPT ); Wed, 19 Jun 2019 08:34:10 -0400 Received: by mail-wr1-f67.google.com with SMTP id x17so3186250wrl.9 for ; Wed, 19 Jun 2019 05:34:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=zkomWHfm2nE4Ls9LrFCC/lbq6EDt2hSMOozA/jG6M0g=; b=fiGw7O31FhJVxqU+t9pw/RP6J9niRaueQ7iIhmJEFeu+iKM4T96BkbHSu8tM+KFgvB 0fPrC+3ya+pxibmHpcr7DJ1vnjGSd/aLz34k9NJuhQ0pE1IpKBvza98umQu+gPkUJrRg 3ghClTEwjP5BNK656jxsJPnQc2TCU0jvem3fhg3cYdY7sOYSkRgeQv5P9S/p73X17n9Q 1vj/0U6BejnNBh3YPv/AjFLXRKPHQ1JXygHV1r/Uh8u0J6sj8LGDDEOSt/blcsikIuyb 7M3OGPAhcJ6xpTm2Qkr+MH7vdiisVsW24tMns/3khP+TPom5T/Dl++Ftli4rcsgGWt0D PtQQ== X-Gm-Message-State: APjAAAUH1S2Yow9n3vOqjxJ590BWySXK8w3JscXOcaJkxFnof4/fsMn1 4yoMkbetKIXrL5ApJCaVF8XZ2w== X-Google-Smtp-Source: APXvYqx7v2CxZ8iyadpYL/pvPW+etAFEjWdVabNUMX4QKPf6eO0WEPIHMZvCJedse968+c6i885NOw== X-Received: by 2002:a5d:488b:: with SMTP id g11mr9807590wrq.72.1560947648011; Wed, 19 Jun 2019 05:34:08 -0700 (PDT) Received: from localhost.localdomain ([151.29.165.245]) by smtp.gmail.com with ESMTPSA id 72sm13469223wrk.22.2019.06.19.05.34.06 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 19 Jun 2019 05:34:07 -0700 (PDT) Date: Wed, 19 Jun 2019 14:34:05 +0200 From: Juri Lelli To: Michal =?iso-8859-1?Q?Koutn=FD?= Cc: peterz@infradead.org, mingo@redhat.com, rostedt@goodmis.org, lizefan@huawei.com, tj@kernel.org, bristot@redhat.com, luca.abeni@santannapisa.it, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched/core: Fix cpu controller for !RT_GROUP_SCHED Message-ID: <20190619123405.GN26005@localhost.localdomain> References: <20190605114935.7683-1-juri.lelli@redhat.com> <20190605142003.GD4255@blackbody.suse.cz> <20190619092904.GB28937@blackbody.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190619092904.GB28937@blackbody.suse.cz> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 19/06/19 11:29, Michal Koutný wrote: > On Wed, Jun 05, 2019 at 04:20:03PM +0200, Michal Koutný wrote: > > I considered relaxing the check to non-root cgroups only, however, as > > your example shows, it doesn't prevent reaching the avoided state by > > other paths. I'm not that familiar with RT sched to tell whether > > RT-priority tasks in different task_groups break any assumptions. > So I had another look and the check is bogus. > > The RT sched with !CONFIG_RT_GROUP_SCHED works only with the struct > rt_rq embedded in the generic struct rq -- regardless of the task's > membership in the cpu controller hierarchy. Yep. > Perhaps, the commit message may mention this also prevents enabling cpu > controller on unified hierarchy (if there are any (kernel) RT tasks to > migrate). Sure. Can add such a comment. > Reviewed-by: Michal Koutný Thanks! Peter? Best, Juri