From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758693Ab3KMTPF (ORCPT ); Wed, 13 Nov 2013 14:15:05 -0500 Received: from merlin.infradead.org ([205.233.59.134]:38248 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754062Ab3KMTO6 (ORCPT ); Wed, 13 Nov 2013 14:14:58 -0500 Date: Wed, 13 Nov 2013 20:14:49 +0100 From: Peter Zijlstra To: Oleg Nesterov Cc: Tejun Heo , David Rientjes , David Laight , Geert Uytterhoeven , Ingo Molnar , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: __refrigerator() && saved task->state Message-ID: <20131113191449.GF16796@laptop.programming.kicks-ass.net> References: <1384264396-14550-1-git-send-email-geert@linux-m68k.org> <20131112141314.GQ5056@laptop.programming.kicks-ass.net> <20131112145243.GU5056@laptop.programming.kicks-ass.net> <20131112162136.GA29065@redhat.com> <20131112165643.GA31278@redhat.com> <20131113032053.GA19394@mtj.dyndns.org> <20131113170724.GA17739@redhat.com> <20131113191143.GA24005@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131113191143.GA24005@redhat.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 13, 2013 at 08:11:43PM +0100, Oleg Nesterov wrote: > At first glance it would be better to simply kill this logic? If > it was called with ->state != 0, the caller is going to schedule() > and it probably executes the wait_event-like code, in this case > it would me more safe to pretend the task got a spurious wakeup? Note that in general the kernel cannot deal with spurious wakeups :/ Most proper locks and wait primitives can, but there's enough open-coded crap out there that can not. I tried..