From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx168.postini.com [74.125.245.168]) by kanga.kvack.org (Postfix) with SMTP id DE7AA6B004A for ; Tue, 10 Apr 2012 16:09:19 -0400 (EDT) Received: by lbao2 with SMTP id o2so207756lba.14 for ; Tue, 10 Apr 2012 13:09:18 -0700 (PDT) Message-ID: <4F84936A.1060708@openvz.org> Date: Wed, 11 Apr 2012 00:09:14 +0400 From: Konstantin Khlebnikov MIME-Version: 1.0 Subject: Re: [PATCH v2] mm: correctly synchronize rss-counters at exit/exec References: <20120409200336.8368.63793.stgit@zurg> <20120410170732.18750.64274.stgit@zurg> <20120410191059.GA5678@redhat.com> In-Reply-To: <20120410191059.GA5678@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Oleg Nesterov Cc: Andrew Morton , Hugh Dickins , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Markus Trippelsdorf , KAMEZAWA Hiroyuki Oleg Nesterov wrote: > On 04/10, Konstantin Khlebnikov wrote: >> >> This patch moves sync_mm_rss() into mm_release(), and moves mm_release() out of >> do_exit() and calls it earlier. After mm_release() there should be no page-faults. > > Can't prove, but I feel there should be a simpler fix... > > Anyway, this patch is not exactly correct. > >> @@ -959,9 +959,10 @@ void do_exit(long code) >> preempt_count()); >> >> acct_update_integrals(tsk); >> - /* sync mm's RSS info before statistics gathering */ >> - if (tsk->mm) >> - sync_mm_rss(tsk->mm); >> + >> + /* Release mm and sync mm's RSS info before statistics gathering */ >> + mm_release(tsk, tsk->mm); > > This breaks kthread_stop() at least. > > The exiting kthread shouldn't do complete_vfork_done() until it > sets ->exit_code. Ouch, I was afraid something like that. > > Oleg. > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org