From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: kosaki.motohiro@jp.fujitsu.com, Andy Whitcroft <apw@shadowen.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Mel Gorman <mel@csn.ul.ie>
Subject: Re: [PATCH 4/4] capture pages freed during direct reclaim for allocation by the reclaimer
Date: Thu, 04 Sep 2008 17:11:38 +0900 [thread overview]
Message-ID: <20080904170016.B265.KOSAKI.MOTOHIRO@jp.fujitsu.com> (raw)
In-Reply-To: <48BEFAF9.3030006@linux-foundation.org>
Hi Cristoph
> How does page allocator fastpath behavior fare with this pathch?
Don't worry it because
1. shrink_zone() isn't fastpath because any reclaim isn't fastpath.
2. buddy combining on __free_one_page() isn't fastpath because
any buddy combining isn't fastpath. (*)
(*)
all modern allocator have delayed buddy combining mecanism
because buddy combining increase cache miss.
(please imazine address X+1 is freed when address X is cold.
combining cause next alloc get address X, then caller see cold page)
at least, allocator's fastpath should avoid its combining IMHO.
Unfortunately the linux buddy's one is limited because
zone->pcp only cache order-0 page.
Then, higher order pages's free always use slow path now.
but it isn't his patch failure.
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next prev parent reply other threads:[~2008-09-04 8:11 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-03 18:44 [RFC PATCH 0/4] Reclaim page capture v2 Andy Whitcroft
2008-09-03 18:44 ` [PATCH 1/4] pull out the page pre-release and sanity check logic for reuse Andy Whitcroft
2008-09-04 1:24 ` Rik van Riel
2008-09-05 1:52 ` KOSAKI Motohiro
2008-09-03 18:44 ` [PATCH 2/4] pull out zone cpuset and watermark checks " Andy Whitcroft
2008-09-04 1:24 ` Rik van Riel
2008-09-05 1:52 ` KOSAKI Motohiro
2008-09-03 18:44 ` [PATCH 3/4] buddy: explicitly identify buddy field use in struct page Andy Whitcroft
2008-09-03 20:36 ` Christoph Lameter
2008-09-04 1:25 ` Rik van Riel
2008-09-05 1:52 ` KOSAKI Motohiro
2008-09-03 18:44 ` [PATCH 4/4] capture pages freed during direct reclaim for allocation by the reclaimer Andy Whitcroft
2008-09-03 20:35 ` Christoph Lameter
2008-09-03 20:53 ` Andy Whitcroft
2008-09-03 21:00 ` Christoph Lameter
2008-09-04 6:38 ` Peter Zijlstra
2008-09-04 14:18 ` Christoph Lameter
2008-09-04 8:11 ` KOSAKI Motohiro [this message]
2008-09-04 8:58 ` Andy Whitcroft
2008-09-04 7:20 ` Peter Zijlstra
2008-09-04 11:35 ` Andy Whitcroft
2008-09-04 7:59 ` KOSAKI Motohiro
2008-09-04 14:44 ` Andy Whitcroft
2008-09-05 1:52 ` KOSAKI Motohiro
-- strict thread matches above, loose matches on Subject: below --
2008-10-01 12:30 [PATCH 0/4] Reclaim page capture v4 Andy Whitcroft
2008-10-01 12:31 ` [PATCH 4/4] capture pages freed during direct reclaim for allocation by the reclaimer Andy Whitcroft
2008-10-01 15:01 ` Christoph Lameter
2008-10-02 14:35 ` Andy Whitcroft
2008-10-02 16:29 ` Christoph Lameter
2008-10-03 3:41 ` KOSAKI Motohiro
2008-10-03 12:37 ` Christoph Lameter
2008-10-02 7:24 ` KAMEZAWA Hiroyuki
2008-10-02 15:02 ` Andy Whitcroft
2008-09-05 10:19 [PATCH 0/4] Reclaim page capture v3 Andy Whitcroft
2008-09-05 10:20 ` [PATCH 4/4] capture pages freed during direct reclaim for allocation by the reclaimer Andy Whitcroft
2008-07-01 17:58 [RFC PATCH 0/4] Reclaim page capture v1 Andy Whitcroft
2008-07-01 17:58 ` [PATCH 4/4] capture pages freed during direct reclaim for allocation by the reclaimer Andy Whitcroft
2008-07-02 12:01 ` KOSAKI Motohiro
2008-07-02 14:44 ` Andy Whitcroft
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