From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx201.postini.com [74.125.245.201]) by kanga.kvack.org (Postfix) with SMTP id D83CE6B0032 for ; Thu, 15 Aug 2013 10:17:00 -0400 (EDT) Received: by mail-pb0-f44.google.com with SMTP id xa7so761609pbc.31 for ; Thu, 15 Aug 2013 07:17:00 -0700 (PDT) Date: Thu, 15 Aug 2013 23:16:53 +0900 From: Minchan Kim Subject: Re: [PATCH] mm: skip the page buddy block instead of one page Message-ID: <20130815141652.GE8437@gmail.com> References: <20130814161642.GM2296@suse.de> <20130814163921.GC2706@gmail.com> <20130814180012.GO2296@suse.de> <520C3DD2.8010905@huawei.com> <20130815024427.GA2718@gmail.com> <520C4EFF.8040305@huawei.com> <20130815041736.GA2592@gmail.com> <20130815113019.GV2296@suse.de> <20130815131935.GA8437@gmail.com> <20130815134209.GW2296@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130815134209.GW2296@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Xishi Qiu , Andrew Morton , riel@redhat.com, aquini@redhat.com, linux-mm@kvack.org, LKML On Thu, Aug 15, 2013 at 02:42:09PM +0100, Mel Gorman wrote: > On Thu, Aug 15, 2013 at 10:19:35PM +0900, Minchan Kim wrote: > > > > > > Why? We're looking for pages to migrate. If the page is free and at the > > > maximum order then there is no point searching in the middle of a free > > > page. > > > > isolate_migratepages_range API works with [low_pfn, end_pfn) > > and we can't guarantee page_order in normal compaction path > > so I'd like to limit the skipping by end_pfn conservatively. > > > > Fine > > s/MAX_ORDER_NR_PAGES/pageblock_nr_pages/ > > and take the min of it and > > low_pfn = min(low_pfn, end_pfn - 1) True. That was really what I suggested to Xishi. Only thing we need it is just number to justify for proving the benefit. Thanks. -- 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/ . Don't email: email@kvack.org