From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f181.google.com (mail-ig0-f181.google.com [209.85.213.181]) by kanga.kvack.org (Postfix) with ESMTP id 846966B007E for ; Thu, 31 Mar 2016 05:38:29 -0400 (EDT) Received: by mail-ig0-f181.google.com with SMTP id nk17so122300919igb.1 for ; Thu, 31 Mar 2016 02:38:29 -0700 (PDT) Received: from szxga02-in.huawei.com (szxga02-in.huawei.com. [119.145.14.65]) by mx.google.com with ESMTPS id 6si9970711igy.14.2016.03.31.02.38.28 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 31 Mar 2016 02:38:29 -0700 (PDT) Message-ID: <56FCEFFE.6040604@huawei.com> Date: Thu, 31 Mar 2016 17:38:06 +0800 From: Xishi Qiu MIME-Version: 1.0 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 Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Linux MM , LKML 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 -- 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