From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757095AbZDWUjb (ORCPT ); Thu, 23 Apr 2009 16:39:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754996AbZDWUi6 (ORCPT ); Thu, 23 Apr 2009 16:38:58 -0400 Received: from mx2.redhat.com ([66.187.237.31]:49235 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754253AbZDWUi4 (ORCPT ); Thu, 23 Apr 2009 16:38:56 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20090423163624.GA6732@redhat.com> References: <20090423163624.GA6732@redhat.com> <1239649429.16771.9.camel@heimdal.trondhjem.org> <20090413181733.GA10424@redhat.com> <32260.1239658818@redhat.com> <20090413214852.GA1127@redhat.com> <1239659841.16771.26.camel@heimdal.trondhjem.org> <20090413222451.GA2758@redhat.com> <14561.1239873018@redhat.com> <21239.1240407420@redhat.com> <5591.1240417398@redhat.com> <20090422175753.GA14236@elte.hu> To: Oleg Nesterov Cc: dhowells@redhat.com, Ingo Molnar , Andrew Morton , serue@us.ibm.com, viro@zeniv.linux.org.uk, "Paul E. McKenney" , Nick Piggin , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Document that wake_up(), complete() and co. imply a full memory barrier Date: Thu, 23 Apr 2009 21:37:14 +0100 Message-ID: <22193.1240519034@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Oleg Nesterov wrote: > Well. I think in that case almost every try_to_wake_up/wake_up_process > needs mb(). Not exactly. They need smp_wmb() in the wake_up() path - unless they use locks, which a lot of cases do. David