From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id CD35C6B01F3 for ; Fri, 2 Apr 2010 15:16:21 -0400 (EDT) Date: Fri, 2 Apr 2010 21:14:14 +0200 From: Oleg Nesterov Subject: Re: [patch] oom: give current access to memory reserves if it has been killed Message-ID: <20100402191414.GA982@redhat.com> References: <20100330154659.GA12416@redhat.com> <20100331175836.GA11635@redhat.com> <20100331204718.GD11635@redhat.com> <20100401135927.GA12460@redhat.com> <20100402111406.GA4432@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: David Rientjes Cc: Andrew Morton , anfei , KOSAKI Motohiro , nishimura@mxp.nes.nec.co.jp, KAMEZAWA Hiroyuki , Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On 04/02, David Rientjes wrote: > > On Fri, 2 Apr 2010, Oleg Nesterov wrote: > > > David, you continue to ignore my arguments ;) select_bad_process() > > must not filter out the tasks with ->mm == NULL. > > > I'm not ignoring your arguments, I think you're ignoring what I'm > responding to. Ah, sorry, I misunderstood your replies. > I prefer to keep oom_badness() to be a positive range as > it always has been (and /proc/pid/oom_score has always used an unsigned > qualifier), Yes, I thought about /proc/pid/oom_score, but imho this is minor issue. We can s/%lu/%ld/ though, or just report 0 if oom_badness() returns -1. Or something. > so I disagree that we need to change oom_badness() to return > anything other than 0 for such tasks. We need to filter them explicitly > in select_bad_process() instead, so please do this there. The problem is, we need task_lock() to pin ->mm. Or, we can change find_lock_task_mm() to do get_task_mm() and return mm_struct *. But then oom_badness() (and proc_oom_score!) needs much more changes, it needs the new "struct mm_struct *mm" argument which is not necessarily equal to p->mm. So, I can't agree. 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/ . Don't email: email@kvack.org