From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx115.postini.com [74.125.245.115]) by kanga.kvack.org (Postfix) with SMTP id 73B3C6B004A for ; Fri, 6 Apr 2012 04:51:31 -0400 (EDT) Received: by yenm8 with SMTP id m8so1553102yen.14 for ; Fri, 06 Apr 2012 01:51:30 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <201204061021.39656.b.zolnierkie@samsung.com> References: <1333643534-1591-1-git-send-email-b.zolnierkie@samsung.com> <1333643534-1591-2-git-send-email-b.zolnierkie@samsung.com> <201204061021.39656.b.zolnierkie@samsung.com> Date: Fri, 6 Apr 2012 17:51:30 +0900 Message-ID: Subject: Re: [PATCH 1/2] mm: compaction: try harder to isolate free pages From: Minchan Kim Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Bartlomiej Zolnierkiewicz Cc: linux-mm@kvack.org, mgorman@suse.de, Kyungmin Park On Fri, Apr 6, 2012 at 5:21 PM, Bartlomiej Zolnierkiewicz wrote: > On Friday 06 April 2012 08:40:56 Minchan Kim wrote: >> On Fri, Apr 6, 2012 at 1:32 AM, Bartlomiej Zolnierkiewicz < >> b.zolnierkie@samsung.com> wrote: >> >> > In isolate_freepages() check each page in a pageblock >> > instead of checking only first pages of pageblock_nr_pages >> > intervals (suitable_migration_target(page) is called before >> > isolate_freepages_block() so if page is "unsuitable" whole >> > pageblock_nr_pages pages will be ommited from the check). >> > It greatly improves possibility of finding free pages to >> > isolate during compaction_alloc() phase. >> > >> >> I doubt how this can help keeping free pages. >> Now, compaction works by pageblock_nr_pages unit so although you work by >> per page, all pages in a block would have same block type. >> It means we can't pass suitable_migration_target. No? > > suitable_migration_target() only checks first page of pageblock_nr_pages > block (1024 normal 4KiB pages in my test case cause there is no hugepage > support on ARM) and pages in pageblock_nr_pages block can have different > types otherwise I would not see improvement from this patch. How? pages in a block should be same type. -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org