From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f178.google.com (mail-wi0-f178.google.com [209.85.212.178]) by kanga.kvack.org (Postfix) with ESMTP id 4B4EB6B0253 for ; Fri, 25 Sep 2015 06:32:06 -0400 (EDT) Received: by wicfx3 with SMTP id fx3so13628935wic.0 for ; Fri, 25 Sep 2015 03:32:05 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id dv8si3725736wib.80.2015.09.25.03.32.04 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 25 Sep 2015 03:32:05 -0700 (PDT) Subject: Re: [PATCH v2 5/9] mm/compaction: allow to scan nonmovable pageblock when depleted state References: <1440382773-16070-1-git-send-email-iamjoonsoo.kim@lge.com> <1440382773-16070-6-git-send-email-iamjoonsoo.kim@lge.com> From: Vlastimil Babka Message-ID: <560522A2.50609@suse.cz> Date: Fri, 25 Sep 2015 12:32:02 +0200 MIME-Version: 1.0 In-Reply-To: <1440382773-16070-6-git-send-email-iamjoonsoo.kim@lge.com> Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mel Gorman , Rik van Riel , David Rientjes , Minchan Kim , Joonsoo Kim On 08/24/2015 04:19 AM, Joonsoo Kim wrote: [...] > > Because we just allow freepage scanner to scan non-movable pageblock > in very limited situation, more scanning events happen. But, allowing > in very limited situation results in a very important benefit that > memory isn't fragmented more than before. Fragmentation effect is > measured on following patch so please refer it. AFAICS it's measured only for the whole series in the cover letter, no? Just to be sure I didn't overlook something. > Signed-off-by: Joonsoo Kim > --- > include/linux/mmzone.h | 1 + > mm/compaction.c | 27 +++++++++++++++++++++++++-- > 2 files changed, 26 insertions(+), 2 deletions(-) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index e13b732..5cae0ad 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -545,6 +545,7 @@ enum zone_flags { > */ > ZONE_FAIR_DEPLETED, /* fair zone policy batch depleted */ > ZONE_COMPACTION_DEPLETED, /* compaction possiblity depleted */ > + ZONE_COMPACTION_SCANALLFREE, /* scan all kinds of pageblocks */ "SCANALLFREE" is hard to read. Otherwise yeah, I agree scanning unmovable pageblocks is necessary sometimes, and this seems to make a reasonable tradeoff. -- 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