From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753254AbbGNJAb (ORCPT ); Tue, 14 Jul 2015 05:00:31 -0400 Received: from mail-wg0-f53.google.com ([74.125.82.53]:36167 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752001AbbGNJA2 (ORCPT ); Tue, 14 Jul 2015 05:00:28 -0400 Date: Tue, 14 Jul 2015 11:00:25 +0200 From: Michal Hocko To: Xishi Qiu Cc: Xuzhichuang , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "Songjiangtao (mygirlsjt)" , "Zhangwei (FF)" Subject: Re: [BUG REPORT] OOM Killer is invoked while the system still has much memory Message-ID: <20150714090025.GA17660@dhcp22.suse.cz> References: <6D317A699782EA4DB9A0E6266C9219696CA2B3BC@SZXEMA501-MBX.china.huawei.com> <20150714081521.GA17711@dhcp22.suse.cz> <55A4CB68.5060906@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55A4CB68.5060906@huawei.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 14-07-15 16:42:16, Xishi Qiu wrote: > On 2015/7/14 16:15, Michal Hocko wrote: > > > On Tue 14-07-15 07:11:34, Xuzhichuang wrote: [...] > >> Jul 10 12:33:03 BMS_CNA04 kernel: [18136514.138968] DMA32: 188513*4kB 29459*8kB 2*16kB 2*32kB 1*64kB 0*128kB 0*256kB 1*512kB 0*1024kB 0*2048kB 0*4096kB = 990396kB > > > > Moreover your allocation request was oreder 2 and you do not have much > > memory there because most of the free memory is in order-0-2. > > > > Hi Michal, > > order=2 -> alloc 16kb memory, and DMA32 still has 2*16kB 2*32kB 1*64kB 1*512kB, > so you mean this large buddy block was reclaimed during the moment of oom and > print, right? Not really. Those high order blocks are inaccessible for your GFP_KERNEL allocation. See __zone_watermark_ok. -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f174.google.com (mail-wi0-f174.google.com [209.85.212.174]) by kanga.kvack.org (Postfix) with ESMTP id 9360B6B0259 for ; Tue, 14 Jul 2015 05:00:30 -0400 (EDT) Received: by wicmv11 with SMTP id mv11so8454060wic.1 for ; Tue, 14 Jul 2015 02:00:30 -0700 (PDT) Received: from mail-wg0-f51.google.com (mail-wg0-f51.google.com. [74.125.82.51]) by mx.google.com with ESMTPS id ba10si1803321wib.29.2015.07.14.02.00.27 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 14 Jul 2015 02:00:28 -0700 (PDT) Received: by wgxm20 with SMTP id m20so3171772wgx.3 for ; Tue, 14 Jul 2015 02:00:27 -0700 (PDT) Date: Tue, 14 Jul 2015 11:00:25 +0200 From: Michal Hocko Subject: Re: [BUG REPORT] OOM Killer is invoked while the system still has much memory Message-ID: <20150714090025.GA17660@dhcp22.suse.cz> References: <6D317A699782EA4DB9A0E6266C9219696CA2B3BC@SZXEMA501-MBX.china.huawei.com> <20150714081521.GA17711@dhcp22.suse.cz> <55A4CB68.5060906@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55A4CB68.5060906@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: Xishi Qiu Cc: Xuzhichuang , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "Songjiangtao (mygirlsjt)" , "Zhangwei (FF)" On Tue 14-07-15 16:42:16, Xishi Qiu wrote: > On 2015/7/14 16:15, Michal Hocko wrote: > > > On Tue 14-07-15 07:11:34, Xuzhichuang wrote: [...] > >> Jul 10 12:33:03 BMS_CNA04 kernel: [18136514.138968] DMA32: 188513*4kB 29459*8kB 2*16kB 2*32kB 1*64kB 0*128kB 0*256kB 1*512kB 0*1024kB 0*2048kB 0*4096kB = 990396kB > > > > Moreover your allocation request was oreder 2 and you do not have much > > memory there because most of the free memory is in order-0-2. > > > > Hi Michal, > > order=2 -> alloc 16kb memory, and DMA32 still has 2*16kB 2*32kB 1*64kB 1*512kB, > so you mean this large buddy block was reclaimed during the moment of oom and > print, right? Not really. Those high order blocks are inaccessible for your GFP_KERNEL allocation. See __zone_watermark_ok. -- Michal Hocko SUSE Labs -- 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