From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id C5A136B0098 for ; Fri, 17 Dec 2010 10:42:20 -0500 (EST) Received: by iwn40 with SMTP id 40so848102iwn.14 for ; Fri, 17 Dec 2010 07:42:19 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <20101213144646.341970461@intel.com> <20101213150329.002158963@intel.com> <20101217021934.GA9525@localhost> <20101217112111.GA8323@localhost> Date: Sat, 18 Dec 2010 00:42:18 +0900 Message-ID: Subject: Re: [PATCH] writeback: skip balance_dirty_pages() for in-memory fs From: Minchan Kim Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Wu Fengguang Cc: Hugh Dickins , Andrew Morton , Jan Kara , Christoph Hellwig , Trond Myklebust , Dave Chinner , Theodore Ts'o , Chris Mason , Peter Zijlstra , Mel Gorman , Rik van Riel , KOSAKI Motohiro , Greg Thelen , linux-mm , "linux-fsdevel@vger.kernel.org" , LKML List-ID: On Sat, Dec 18, 2010 at 12:34 AM, Minchan Kim wrote= : > On Fri, Dec 17, 2010 at 8:21 PM, Wu Fengguang wr= ote: >> This avoids unnecessary checks and dirty throttling on tmpfs/ramfs. >> >> It also prevents >> >> [ =A0388.126563] BUG: unable to handle kernel NULL pointer dereference a= t 0000000000000050 >> >> in the balance_dirty_pages tracepoint, which will call >> >> =A0 =A0 =A0 =A0dev_name(mapping->backing_dev_info->dev) >> >> but shmem_backing_dev_info.dev is NULL. >> >> CC: Hugh Dickins >> Signed-off-by: Wu Fengguang > Reviewed-by: Minchan Kim > > Is it a material for -stable? No. balance_dirty_pages tracepoint is new. :) > > -- > Kind regards, > Minchan Kim > --=20 Kind regards, Minchan Kim -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org