From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751905AbXDKJxw (ORCPT ); Wed, 11 Apr 2007 05:53:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751908AbXDKJxv (ORCPT ); Wed, 11 Apr 2007 05:53:51 -0400 Received: from ug-out-1314.google.com ([66.249.92.173]:15644 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751905AbXDKJxu (ORCPT ); Wed, 11 Apr 2007 05:53:50 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=Yxfzhz3PejhqdLjMkGb8cQy90Ed/vx5bPaQj/qKhrO7CxlcBJMdxMEfLuHFMy/wr/dr1SeSjoNp9dbPRwBQypAG9v7MpL5B98ANrMa4HOVf7flWVaReX2dxNXzi7HLLclM1eynWH5UMIDgMwGWhyBfOlydoKqQJkmg08hDJOYUk= Message-ID: Date: Wed, 11 Apr 2007 17:53:49 +0800 From: "Zhao Forrest" To: "Pekka Enberg" Subject: Re: Why kmem_cache_free occupy CPU for more than 10 seconds? Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org In-Reply-To: <84144f020704102353r7dcc3538u2e34237d3496630e@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <84144f020704102353r7dcc3538u2e34237d3496630e@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I got some new information: Before soft lockup message is out, we have: [root@nsgsh-dhcp-149 home]# cat /proc/slabinfo |grep buffer_head buffer_head 10927942 10942560 120 32 1 : tunables 32 16 8 : slabdata 341955 341955 6 : globalstat 37602996 11589379 1174373 6 0 1 6918 12166031 1013708 : cpustat 35254590 2350698 13610965 907286 Then after buffer_head is freed, we have: [root@nsgsh-dhcp-149 home]# cat /proc/slabinfo |grep buffer_head buffer_head 9542 36384 120 32 1 : tunables 32 16 8 : slabdata 1137 1137 245 : globalstat 37602996 11589379 1174373 6 0 1 6983 20507478 1708818 : cpustat 35254625 2350704 16027174 1068367 Does this huge number of buffer_head cause the soft lockup? Thanks, Forrest On 4/11/07, Pekka Enberg wrote: > On 4/11/07, Zhao Forrest wrote: > > We're using RHEL5 with kernel version 2.6.18-8.el5. > > When doing a stress test on raw device for about 3-4 hours, we found > > the soft lockup message in dmesg. > > I know we're not reporting the bug on the latest kernel, but does any > > expert know if this is the known issue in old kernel? Or why > > kmem_cache_free occupy CPU for more than 10 seconds? > > Sounds like slab corruption. CONFIG_DEBUG_SLAB should tell you more. >