From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f180.google.com (mail-pd0-f180.google.com [209.85.192.180]) by kanga.kvack.org (Postfix) with ESMTP id A179F6B0031 for ; Thu, 19 Dec 2013 00:45:23 -0500 (EST) Received: by mail-pd0-f180.google.com with SMTP id q10so656900pdj.25 for ; Wed, 18 Dec 2013 21:45:23 -0800 (PST) Received: from e28smtp01.in.ibm.com (e28smtp01.in.ibm.com. [122.248.162.1]) by mx.google.com with ESMTPS id xh9si1680140pab.325.2013.12.18.21.45.20 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 18 Dec 2013 21:45:22 -0800 (PST) Received: from /spool/local by e28smtp01.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 19 Dec 2013 11:15:15 +0530 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 82321E0059 for ; Thu, 19 Dec 2013 11:17:38 +0530 (IST) Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id rBJ5j5qX196976 for ; Thu, 19 Dec 2013 11:15:05 +0530 Received: from d28av04.in.ibm.com (localhost [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id rBJ5jAt7026130 for ; Thu, 19 Dec 2013 11:15:11 +0530 Date: Thu, 19 Dec 2013 13:45:09 +0800 From: Wanpeng Li Subject: Re: [PATCH v2] mm/rmap: fix BUG at rmap_walk Message-ID: <52b287f2.29a0420a.2738.5775SMTPIN_ADDED_BROKEN@mx.google.com> Reply-To: Wanpeng Li References: <1387424720-22826-1-git-send-email-liwanp@linux.vnet.ibm.com> <20131219042902.GA27512@hacker.(null)> <52B27D48.9030703@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52B27D48.9030703@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: Bob Liu , Andrew Morton , Hugh Dickins , Joonsoo Kim , Linux-MM , Linux-Kernel On Wed, Dec 18, 2013 at 11:59:52PM -0500, Sasha Levin wrote: >On 12/18/2013 11:29 PM, Wanpeng Li wrote: >>>PageLocked is not required by page_referenced_anon() and there is not >>>>any assertion before, commit 37f093cdf introduced this extra BUG_ON() >>There are two callsites shrink_active_list and page_check_references() >>of page_referenced(). shrink_active_list and its callee won't lock anonymous >>page, however, page_check_references() is called with anonymous page >>lock held in shrink_page_list. So page_check_references case need >>specail handling. > >This explanation seems to be based on current observed behaviour. > >I think it would be easier if you could point out the actual code in each >function that requires a page to be locked, once we have that we don't have >to care about what the callers currently do. > rmap_walk_anon() itself don't need to hold page lock. I remove it in v3. Regards, Wanpeng Li > >Thanks, >Sasha -- 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