Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755283Ab2FNBtu (ORCPT ); Wed, 13 Jun 2012 21:49:50 -0400 Received: from LGEMRELSE6Q.lge.com ([156.147.1.121]:45875 "EHLO LGEMRELSE6Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755045Ab2FNBts (ORCPT ); Wed, 13 Jun 2012 21:49:48 -0400 X-AuditID: 9c930179-b7bb9ae000000ea5-6b-4fd9433a627d Message-ID: <4FD9433C.4060503@kernel.org> Date: Thu, 14 Jun 2012 10:49:48 +0900 From: Minchan Kim User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 Newsgroups: gmane.linux.kernel.mm,gmane.linux.kernel To: Andrea Arcangeli CC: Kamezawa Hiroyuki , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mel Gorman , Michal Hocko Subject: Re: [PATCH] mm: do not use page_count without a page pin References: <1339373872-31969-1-git-send-email-minchan@kernel.org> <4FD59C31.6000606@jp.fujitsu.com> <20120611074440.GI3094@redhat.com> <20120611133043.GA2340@barrios> <20120611144132.GT3094@redhat.com> <4FD675FE.1060202@kernel.org> <20120614012103.GY3094@redhat.com> In-Reply-To: <20120614012103.GY3094@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1395 Lines: 32 On 06/14/2012 10:21 AM, Andrea Arcangeli wrote: > On Tue, Jun 12, 2012 at 07:49:34AM +0900, Minchan Kim wrote: >> If THP page isn't LRU and it's still PageTransHuge, I think it's rather rare and >> although it happens, it means migration/reclaimer is about to split or isolate/putback >> so it ends up making THP page movable pages. >> >> IMHO, it would be better to account it by movable pages. >> What do you think about it? > > Agreed. Besides THP don't fragment pageblocks. It was just about > speeding up the scanning the same way it happens with the pagebuddy > check, but probably not worth it because we're in a racy area here not > holding locks. pagebuddy is safe because the zone lock is hold, or > it'd run in the same problem. Yeb. zone lock is already hold so pagebuddy check is safe but THP still in a racy so let's leave it as it is. If you don't have concern about this patch any more, could you add Acked-by in my latest patch for Andrew to pick up? Although you have a concern, let's make it as separate patch because it's optimization patch and other patch is pending by this. Thanks, Andrea. -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/