From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756952AbcCaJi0 (ORCPT ); Thu, 31 Mar 2016 05:38:26 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:58057 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756927AbcCaJiV (ORCPT ); Thu, 31 Mar 2016 05:38:21 -0400 Message-ID: <56FCEFFE.6040604@huawei.com> Date: Thu, 31 Mar 2016 17:38:06 +0800 From: Xishi Qiu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Michal Hocko CC: Linux MM , LKML Subject: Re: [RFC] oom, but there is enough memory References: <56FCEAD0.9080806@huawei.com> <20160331093011.GC27831@dhcp22.suse.cz> In-Reply-To: <20160331093011.GC27831@dhcp22.suse.cz> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020201.56FCF003.0108,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: b273677df228d2a5940f836c18c890b4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016/3/31 17:30, Michal Hocko wrote: > On Thu 31-03-16 17:16:00, Xishi Qiu wrote: >> It triggers a lot of ooms, but there is enough memory(many large blocks). >> And at last "Kernel panic - not syncing: Out of memory and no killable processes..." >> >> I find almost the every call trace include "pagefault_out_of_memory" and "gfp_mask=0x0". >> If it does oom, why not it triger in mm core path? > > It seems that somebody in the page fault path has returned with > VM_FAULT_OOM without invoking the page allocator and kept returning the > same error until there is nothing killable and so the oom killer panics. > > [...] >> <4>[63651.040374s][pid:2912,cpu3,sh]DMA free:550600kB min:5244kB low:27580kB high:28892kB active_anon:343060kB inactive_anon:1224kB active_file:107596kB inactive_file:465156kB unevictable:1040kB isolated(anon):0kB isolated(file):0kB present:2016252kB managed:1720040kB mlocked:1040kB dirty:40kB writeback:0kB mapped:200420kB shmem:1312kB slab_reclaimable:27048kB slab_unreclaimable:73300kB kernel_stack:15248kB pagetables:14484kB unstable:0kB bounce:0kB free_cma:30896kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no > > This is rather weird. DMA zone with 2GB? What kind of architecture is > this? Hi Michal, It's arm64, so DMA is [0-4G], and Normal is [4G-] Is that something wrong with the RAM hardware, then trigger the problem? Thanks, Xishi Qiu