From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751195Ab3LXGHK (ORCPT ); Tue, 24 Dec 2013 01:07:10 -0500 Received: from LGEMRELSE7Q.lge.com ([156.147.1.151]:57555 "EHLO LGEMRELSE7Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750985Ab3LXGHH (ORCPT ); Tue, 24 Dec 2013 01:07:07 -0500 X-AuditID: 9c930197-b7c4aae000003d84-a6-52b924884b6f Date: Tue, 24 Dec 2013 15:07:05 +0900 From: Joonsoo Kim To: Sasha Levin Cc: Andrew Morton , "linux-mm@kvack.org" , khlebnikov@openvz.org, LKML , Wanpeng Li , Bob Liu Subject: Re: mm: kernel BUG at include/linux/swapops.h:131! Message-ID: <20131224060705.GA16140@lge.com> References: <52B1C143.8080301@oracle.com> <52B871B2.7040409@oracle.com> <20131224025127.GA2835@lge.com> <52B8F8F6.1080500@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52B8F8F6.1080500@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 23, 2013 at 10:01:10PM -0500, Sasha Levin wrote: > On 12/23/2013 09:51 PM, Joonsoo Kim wrote: > >On Mon, Dec 23, 2013 at 12:24:02PM -0500, Sasha Levin wrote: > >>>Ping? > >>> > >>>I've also Cc'ed the "this page shouldn't be locked at all" team. > >Hello, > > > >I can't find the reason of this problem. > >If it is reproducible, how about bisecting? > > While it reproduces under fuzzing it's pretty hard to bisect it with > the amount of issues uncovered by trinity recently. > > I can add any debug code to the site of the BUG if that helps. Good! It will be helpful to add dump_page() in migration_entry_to_page(). Thanks. --------8<------ diff --git a/include/linux/swapops.h b/include/linux/swapops.h index c0f7526..f695abc 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -3,6 +3,7 @@ #include #include +#include /* * swapcache pages are stored in the swapper_space radix tree. We want to @@ -128,6 +129,8 @@ static inline struct page *migration_entry_to_page(swp_entry_t entry) * Any use of migration entries may only occur while the * corresponding page is locked */ + if (!PageLocked(p)) + dump_page(p); BUG_ON(!PageLocked(p)); return p; }