From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750957AbaETFI7 (ORCPT ); Tue, 20 May 2014 01:08:59 -0400 Received: from forward1m.mail.yandex.net ([37.140.138.1]:35042 "EHLO forward1m.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750699AbaETFI6 (ORCPT ); Tue, 20 May 2014 01:08:58 -0400 From: Kirill Tkhai To: Peter Zijlstra Cc: Juri Lelli , "linux-kernel@vger.kernel.org" , "mingo@redhat.com" , "stable@vger.kernel.org" In-Reply-To: <20140520000026.GD11096@twins.programming.kicks-ass.net> References: <20140516213003.10384.7946.stgit@localhost> <20140519151233.5043b749361e1b384f1e5562@gmail.com> <783871400527879@web2j.yandex.ru> <20140520000026.GD11096@twins.programming.kicks-ass.net> Subject: Re: [PATCH] sched/dl: Fix race between dl_task_timer() and sched_setaffinity() MIME-Version: 1.0 Message-Id: <1413311400562533@web30m.yandex.ru> X-Mailer: Yamail [ http://yandex.ru ] 5.0 Date: Tue, 20 May 2014 09:08:53 +0400 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=koi8-r Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 20.05.2014, 04:00, "Peter Zijlstra" : > On Mon, May 19, 2014 at 11:31:19PM +0400, Kirill Tkhai wrote: > >> š@@ -513,9 +513,17 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer) >> šššššššššššššššššššššššššššššššššššššššššššššššššššššššstruct sched_dl_entity, >> šššššššššššššššššššššššššššššššššššššššššššššššššššššššdl_timer); >> ššššššššššstruct task_struct *p = dl_task_of(dl_se); >> š- struct rq *rq = task_rq(p); >> š+ struct rq *rq; >> š+again: >> š+ rq = task_rq(p); >> ššššššššššraw_spin_lock(&rq->lock); >> >> š+ if (unlikely(rq != task_rq(p))) { >> š+ /* Task was moved, retrying. */ >> š+ raw_spin_unlock(&rq->lock); >> š+ goto again; >> š+ } >> š+ > > That thing is called: rq = __task_rq_lock(p); But p->pi_lock is not held. The problem is __task_rq_lock() has lockdep assert. Should we change it? Kirill