Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753178AbZKLPAn (ORCPT ); Thu, 12 Nov 2009 10:00:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753109AbZKLPAj (ORCPT ); Thu, 12 Nov 2009 10:00:39 -0500 Received: from casper.infradead.org ([85.118.1.10]:44124 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753084AbZKLPAj (ORCPT ); Thu, 12 Nov 2009 10:00:39 -0500 Subject: Re: [PATCH] fix granularity of task_u/stime(), v2 From: Peter Zijlstra To: Stanislaw Gruszka Cc: Hidetoshi Seto , =?ISO-8859-1?Q?Am=E9rico?= Wang , Spencer Candland , linux-kernel@vger.kernel.org, Ingo Molnar , Oleg Nesterov In-Reply-To: <20091112144919.GA6218@dhcp-lab-161.englab.brq.redhat.com> References: <4AF26176.4080307@jp.fujitsu.com> <1257778154.4108.341.camel@laptop> <4AF8FD3C.2090008@jp.fujitsu.com> <4AF8FE76.406@jp.fujitsu.com> <20091111121150.GA2549@dhcp-lab-161.englab.brq.redhat.com> <4AFB5019.7030901@jp.fujitsu.com> <4AFB77C2.8080705@jp.fujitsu.com> <2375c9f90911111855w20491a1er8d3400cf4e027855@mail.gmail.com> <4AFB8C21.6080404@jp.fujitsu.com> <4AFB9029.9000208@jp.fujitsu.com> <20091112144919.GA6218@dhcp-lab-161.englab.brq.redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 12 Nov 2009 16:00:38 +0100 Message-ID: <1258038038.4039.467.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1862 Lines: 47 On Thu, 2009-11-12 at 15:49 +0100, Stanislaw Gruszka wrote: > I can not reproduce > the bug with below patch: > > diff --git a/kernel/exit.c b/kernel/exit.c > index f7864ac..b85e384 100644 > --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -110,8 +110,8 @@ static void __exit_signal(struct task_struct *tsk) > * We won't ever get here for the group leader, since it > * will have been the last reference on the signal_struct. > */ > - sig->utime = cputime_add(sig->utime, task_utime(tsk)); > - sig->stime = cputime_add(sig->stime, task_stime(tsk)); > + sig->utime = cputime_add(sig->utime, tsk->utime); //task_utime(tsk)); > + sig->stime = cputime_add(sig->stime, tsk->stime); //task_stime(tsk)); > sig->gtime = cputime_add(sig->gtime, task_gtime(tsk)); > sig->min_flt += tsk->min_flt; > sig->maj_flt += tsk->maj_flt; Yes, this is the thing I suggested and makes sense. > diff --git a/kernel/sys.c b/kernel/sys.c > index ce17760..8be5b75 100644 > --- a/kernel/sys.c > +++ b/kernel/sys.c > @@ -914,8 +914,8 @@ void do_sys_times(struct tms *tms) > struct task_cputime cputime; > cputime_t cutime, cstime; > > - thread_group_cputime(current, &cputime); > spin_lock_irq(¤t->sighand->siglock); > + thread_group_cputime(current, &cputime); > cutime = current->signal->cutime; > cstime = current->signal->cstime; > spin_unlock_irq(¤t->sighand->siglock); > > Perhaps we can remove task_{u,s}time() in some places or maybe at whole ? I think task_[us]time() still has value for getrusage() since it avoids the task hiding from top by never running during the tick crap. -- 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/