From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765163AbZFLNwt (ORCPT ); Fri, 12 Jun 2009 09:52:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934421AbZFLNvg (ORCPT ); Fri, 12 Jun 2009 09:51:36 -0400 Received: from mx2.redhat.com ([66.187.237.31]:38040 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934429AbZFLNvf (ORCPT ); Fri, 12 Jun 2009 09:51:35 -0400 Date: Fri, 12 Jun 2009 15:46:26 +0200 From: Oleg Nesterov To: Stanislaw Gruszka Cc: Thomas Gleixner , "linux-kernel@vger.kernel.org" , Peter Zijlstra , Ingo Molnar , Andrew Morton Subject: Re: [PATCH 1/2] posix-cpu-timers: avoid do_sys_times() races with __exit_signal() Message-ID: <20090612134626.GA3784@redhat.com> References: <20090612103403.2e1d576f@dhcp-lab-109.englab.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090612103403.2e1d576f@dhcp-lab-109.englab.brq.redhat.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 On 06/12, Stanislaw Gruszka wrote: > > Protect thread_group_cputime() call by siglock, to avoid possible (but > to be honest - very improbable) double times accounting of exiting task. > This is revert of commit 2b5fe6de58276d0b5a7c884d5dbfc300ca47db78 > "thread_group_cputime: move a couple of callsites outside of ->siglock", > but implementation of thread_group_cputime() was different then. Yes, at that time thread_group_cputime() was reading per-cpu data, and ->siglock was unneeded. I think the patch is correct. Oleg.