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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 B5566C5B57D for ; Tue, 2 Jul 2019 07:01:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 91AAC2146F for ; Tue, 2 Jul 2019 07:01:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727087AbfGBHBd (ORCPT ); Tue, 2 Jul 2019 03:01:33 -0400 Received: from mail-wm1-f68.google.com ([209.85.128.68]:34973 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725845AbfGBHBc (ORCPT ); Tue, 2 Jul 2019 03:01:32 -0400 Received: by mail-wm1-f68.google.com with SMTP id c6so1978251wml.0 for ; Tue, 02 Jul 2019 00:01:31 -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:in-reply-to:user-agent; bh=7BmWpWsMHr5JYuSho9C6rnA1huvO7+aSrMupO2ViFEI=; b=Wy2dDc8QM3DZ2jGjkG2sfb+7aUq37lqEWc+w7vtWQNewM1BpKC7o2U+1jEEg8kXaqh lKWiKIwOeq15MTUPxsYH814yy/2TGyqSg9B6VSD16qzq4MMascLtoYNDIN6J63yKpYVF 9q84mZm/FgVdUOwFt0lisz76Ur2y30d5r01ht8SLfKzCErX9dGkj95aqUZSyoqUF2W94 1GuDpci6RDjH0SPtv/Lt0nUfI5dA0DEA6bldPWr3M6w2tfFAFKggng3CTgbxbGEppWRR bJLdWnoUGUtBO2dV+JU/TTA3cLdA0EPNJzzptp7lL86uy+FqhObN6vzzw2qxP/kudhyl Iy2w== X-Gm-Message-State: APjAAAXjHFA27SOW5y0eNdz0+0MohN+eNbOOZ2pE0q+PHjDXvCGFZts9 7k4q7d7vMnp0/bPum8dzPnIGRA== X-Google-Smtp-Source: APXvYqxX3h0O/1RbPglcXFFfIUbuhS5iGSJGJV+SQNR4zsijY3wxjzid5bLZJjgEp5J82pyyIoCJtA== X-Received: by 2002:a1c:720e:: with SMTP id n14mr2168055wmc.53.1562050890608; Tue, 02 Jul 2019 00:01:30 -0700 (PDT) Received: from localhost.localdomain ([151.15.224.253]) by smtp.gmail.com with ESMTPSA id d10sm14299306wro.18.2019.07.02.00.01.29 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 02 Jul 2019 00:01:30 -0700 (PDT) Date: Tue, 2 Jul 2019 09:01:28 +0200 From: Juri Lelli To: Peter Zijlstra Cc: mingo@redhat.com, rostedt@goodmis.org, tj@kernel.org, linux-kernel@vger.kernel.org, luca.abeni@santannapisa.it, claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it, bristot@redhat.com, mathieu.poirier@linaro.org, lizefan@huawei.com, cgroups@vger.kernel.org Subject: Re: [PATCH v8 8/8] rcu/tree: Setschedule gp ktread to SCHED_FIFO outside of atomic region Message-ID: <20190702070128.GG26005@localhost.localdomain> References: <20190628080618.522-1-juri.lelli@redhat.com> <20190628080618.522-9-juri.lelli@redhat.com> <20190701191308.GE3402@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190701191308.GE3402@hirez.programming.kicks-ass.net> 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 On 01/07/19 21:13, Peter Zijlstra wrote: > On Fri, Jun 28, 2019 at 10:06:18AM +0200, Juri Lelli wrote: > > sched_setscheduler() needs to acquire cpuset_rwsem, but it is currently > > called from an invalid (atomic) context by rcu_spawn_gp_kthread(). > > > > Fix that by simply moving sched_setscheduler_nocheck() call outside of > > the atomic region, as it doesn't actually require to be guarded by > > rcu_node lock. > > Maybe move this earlier in the series such that the bug doesn't manifest > in bisection? OK.