From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id E546D6B00E7 for ; Tue, 18 Jan 2011 20:17:52 -0500 (EST) Message-id: In-Reply-To: <20110119094813.2ea20439.kamezawa.hiroyu@jp.fujitsu.com> References: <20110118152844.88cfdc2c.akpm@linux-foundation.org> <20110119092733.4927f935.nishimura@mxp.nes.nec.co.jp> <20110119094813.2ea20439.kamezawa.hiroyu@jp.fujitsu.com> Date: Wed, 19 Jan 2011 10:11:12 +0900 From: nishimura@mxp.nes.nec.co.jp Subject: Re: [PATCH v4] mm: add replace_page_cache_page() function MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Miklos Szeredi , minchan.kim@gmail.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Daisuke Nishimura List-ID: > On Wed, 19 Jan 2011 09:27:33 +0900 > Daisuke Nishimura wrote: > >> On Tue, 18 Jan 2011 15:28:44 -0800 >> Andrew Morton wrote: >> >> > On Tue, 18 Jan 2011 12:18:11 +0100 >> > Miklos Szeredi wrote: >> > >> > > +int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask) >> > > +{ >> > > + int error; >> > > + struct mem_cgroup *memcg = NULL; >> > >> > I'm suspecting that the unneeded initialisation was added to suppress a >> > warning? >> > >> No. >> It's necessary for mem_cgroup_{prepare|end}_migration(). >> mem_cgroup_prepare_migration() will return without doing anything in >> "if (mem_cgroup_disabled()" case(iow, "memcg" is not overwritten), >> but mem_cgroup_end_migration() depends on the value of "memcg" to decide >> whether prepare_migration has succeeded or not. >> This may not be a good implementation, but IMHO I'd like to to initialize >> valuable before using it in general. >> > > I think it can be initlized in mem_cgroup_prepare_migration(). > I'll send patch later. > I see, thanks. I think you know it, but just a note: mem_cgroup_{try_charge|commit_charge}_swapin() use the same logic, so try_charge_swapin() should also be changed for consistency. Thanks, Daisuke Nishimura. -- 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