From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id BD2E76B0078 for ; Tue, 16 Feb 2010 21:58:24 -0500 (EST) Received: from spaceape7.eur.corp.google.com (spaceape7.eur.corp.google.com [172.28.16.141]) by smtp-out.google.com with ESMTP id o1H2wNtN006586 for ; Tue, 16 Feb 2010 18:58:23 -0800 Received: from pzk26 (pzk26.prod.google.com [10.243.19.154]) by spaceape7.eur.corp.google.com with ESMTP id o1H2w3B7000973 for ; Tue, 16 Feb 2010 18:58:21 -0800 Received: by pzk26 with SMTP id 26so2773845pzk.25 for ; Tue, 16 Feb 2010 18:58:21 -0800 (PST) Date: Tue, 16 Feb 2010 18:58:17 -0800 (PST) From: David Rientjes Subject: Re: [patch -mm 4/9 v2] oom: remove compulsory panic_on_oom mode In-Reply-To: <20100217113430.9528438d.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: References: <20100216090005.f362f869.kamezawa.hiroyu@jp.fujitsu.com> <20100216092311.86bceb0c.kamezawa.hiroyu@jp.fujitsu.com> <20100217084239.265c65ea.kamezawa.hiroyu@jp.fujitsu.com> <20100217090124.398769d5.kamezawa.hiroyu@jp.fujitsu.com> <20100217094137.a0d26fbb.kamezawa.hiroyu@jp.fujitsu.com> <20100217111319.d342f10e.kamezawa.hiroyu@jp.fujitsu.com> <20100217113430.9528438d.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Rik van Riel , Nick Piggin , Andrea Arcangeli , Balbir Singh , Lubos Lunak , KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Wed, 17 Feb 2010, KAMEZAWA Hiroyuki wrote: > > We want to lock all populated zones with ZONE_OOM_LOCKED to avoid > > needlessly killing more than one task regardless of how many memcgs are > > oom. > > > Current implentation archive what memcg want. Why remove and destroy memcg ? > I've updated my patch to not take ZONE_OOM_LOCKED for any zones on memcg oom. I'm hoping that you will add sysctl_panic_on_oom == 2 for this case later, however. > What I mean is > - What VM_FAULT_OOM means is not "memory is exhausted" but "something is exhausted". > > For example, when hugepages are all used, it may return VM_FAULT_OOM. > Especially when nr_overcommit_hugepage == usage_of_hugepage, it returns VM_FAULT_OOM. > The hugetlb case seems to be the only misuse of VM_FAULT_OOM where it doesn't mean we simply don't have the memory to handle the page fault, i.e. your earlier "memory is exhausted" definition. That was handled well before calling out_of_memory() by simply killing current since we know it is faulting hugetlb pages and its resource is limited. We could pass the vma to pagefault_out_of_memory() and simply kill current if its killable and is_vm_hugetlb_page(vma). -- 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