From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965755AbXCPRX7 (ORCPT ); Fri, 16 Mar 2007 13:23:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965771AbXCPRX7 (ORCPT ); Fri, 16 Mar 2007 13:23:59 -0400 Received: from pfx2.jmh.fr ([194.153.89.55]:58058 "EHLO pfx2.jmh.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965755AbXCPRX6 (ORCPT ); Fri, 16 Mar 2007 13:23:58 -0400 From: Eric Dumazet To: Oleg Nesterov Subject: Re: + getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible.patch added to -mm tree Date: Fri, 16 Mar 2007 18:23:57 +0100 User-Agent: KMail/1.9.5 Cc: Andrew Morton , linux-kernel@vger.kernel.org References: <20070316171023.GA218@tv-sign.ru> In-Reply-To: <20070316171023.GA218@tv-sign.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200703161823.57858.dada1@cosmosbay.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 16 March 2007 18:10, Oleg Nesterov wrote: > Eric Dumazet wrote: > > @@ -2021,6 +2022,8 @@ static void k_getrusage(struct task_stru > > r->ru_nivcsw = p->signal->cnivcsw; > > r->ru_minflt = p->signal->cmin_flt; > > r->ru_majflt = p->signal->cmaj_flt; > > + r->ru_inblock = task_io_get_inblock(p); > > + r->ru_oublock = task_io_get_oublock(p); > > > > if (who == RUSAGE_CHILDREN) > > break; > > @@ -2032,6 +2035,8 @@ static void k_getrusage(struct task_stru > > r->ru_nivcsw += p->signal->nivcsw; > > r->ru_minflt += p->signal->min_flt; > > r->ru_majflt += p->signal->maj_flt; > > + r->ru_inblock += task_io_get_inblock(p); > > + r->ru_oublock += task_io_get_oublock(p); > > t = p; > > do { > > utime = cputime_add(utime, t->utime); > > @@ -2040,6 +2045,8 @@ static void k_getrusage(struct task_stru > > r->ru_nivcsw += t->nivcsw; > > r->ru_minflt += t->min_flt; > > r->ru_majflt += t->maj_flt; > > + r->ru_inblock += task_io_get_inblock(t); > > + r->ru_oublock += task_io_get_oublock(t); > > I can't understand this. Consider k_getrusage(RUSAGE_BOTH). The end result > is that r->ru_inblock == 3 * task_io_get_inblock(p). > > No? Yes :) Very good point, you found a bug in k_getrusage(). I just followed the existing logic, but it seems this logic is bad. So not only ru_inblock/ru_oublock are multiplied by 3 : others fields as well are wrong. Also the definition of RUSAGE_CHILDREN is not conformant to standard http://www.opengroup.org/onlinepubs/009695399/functions/getrusage.html "If the value of the who argument is RUSAGE_CHILDREN, information shall be "returned about resources used by the terminated and waited-for children of "the current process We currently do a sum of rusage stats of still alive children.. thats totally wrong... Eric