Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756374AbYJQPet (ORCPT ); Fri, 17 Oct 2008 11:34:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755156AbYJQPek (ORCPT ); Fri, 17 Oct 2008 11:34:40 -0400 Received: from wavehammer.waldi.eu.org ([82.139.201.20]:37426 "EHLO wavehammer.waldi.eu.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754684AbYJQPej (ORCPT ); Fri, 17 Oct 2008 11:34:39 -0400 Date: Fri, 17 Oct 2008 17:34:36 +0200 From: Bastian Blank To: Martin Schwidefsky Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-arch@vger.kernel.org, Heiko Carstens Subject: Re: [patch 2/2] introduce vdso on s390 Message-ID: <20081017153436.GA17116@wavehammer.waldi.eu.org> Mail-Followup-To: Bastian Blank , Martin Schwidefsky , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-arch@vger.kernel.org, Heiko Carstens References: <20081015174506.107691579@de.ibm.com> <20081015175305.332585239@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20081015175305.332585239@de.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1043 Lines: 32 On Wed, Oct 15, 2008 at 07:45:08PM +0200, Martin Schwidefsky wrote: > +void update_vsyscall(struct timespec *wall_time, struct clocksource *clock) > +{ > + if (clock != &clocksource_tod) > + return; > + > + /* Make userspace gettimeofday spin until we're done. */ > + ++vdso_data->tb_update_count; > + smp_mb(); > + vdso_data->xtime_tod_stamp = clock->cycle_last; > + vdso_data->xtime_clock_sec = xtime.tv_sec; > + vdso_data->xtime_clock_nsec = xtime.tv_nsec; > + vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; > + vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; > + smp_wmb(); Different barriers? > + ++(vdso_data->tb_update_count); Why ++(...)? Bastian -- Either one of us, by himself, is expendable. Both of us are not. -- Kirk, "The Devil in the Dark", stardate 3196.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/