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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 EAD63C0650E for ; Mon, 1 Jul 2019 19:13:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C38A22146F for ; Mon, 1 Jul 2019 19:13:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="UpqdSARn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726811AbfGATNp (ORCPT ); Mon, 1 Jul 2019 15:13:45 -0400 Received: from merlin.infradead.org ([205.233.59.134]:38282 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726587AbfGATNp (ORCPT ); Mon, 1 Jul 2019 15:13:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=ipn4fix027HY4nDGg4ZOEnVhpfAVctRuNAZ2QjAiS5g=; b=UpqdSARnV7FfcONeqXzNCy0EI DfBNv33im8tXzEphgieqWUaMIsGAxnYOm3bob+51nLyp246R8hWDi1sDgf6lr5YWFlKF3SghT0ZzS Vx4XeXfvRzye3mgCOEVb9nT4RD6e/jCwHRnOyln5a6SzTPCmLM2l2F0bxPIn5yc+9lfGZSq5oF3m6 HfNRaDqnEp49sOihn9f3VpVRCQT98ipZe+y2YVbYE/Xg+2cYU5SOA6kIlSv057KtYGVYAHMFQpaB0 jeaBCwJAWMs746NOdgU9Vwmime6gqDOmoME02wIW7L+fr0VnFxga0ZhmC4ulwqy5AESxXmnGWftB6 ZEjI4QNuA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hi1jh-0001s4-OA; Mon, 01 Jul 2019 19:13:09 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7148020963E39; Mon, 1 Jul 2019 21:13:08 +0200 (CEST) Date: Mon, 1 Jul 2019 21:13:08 +0200 From: Peter Zijlstra To: Juri Lelli 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: <20190701191308.GE3402@hirez.programming.kicks-ass.net> References: <20190628080618.522-1-juri.lelli@redhat.com> <20190628080618.522-9-juri.lelli@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190628080618.522-9-juri.lelli@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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?