From: Christoph Lameter <cl@linux.com>
To: Mel Gorman <mgorman@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>,
Linux-Netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
David Miller <davem@davemloft.net>, Neil Brown <neilb@suse.de>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Pekka Enberg <penberg@cs.helsinki.fi>
Subject: Re: [PATCH 02/15] mm: sl[au]b: Add knowledge of PFMEMALLOC reserve pages
Date: Wed, 8 Feb 2012 09:14:32 -0600 (CST) [thread overview]
Message-ID: <alpine.DEB.2.00.1202080907320.30248@router.home> (raw)
In-Reply-To: <20120208144506.GI5938@suse.de>
On Wed, 8 Feb 2012, Mel Gorman wrote:
> o struct kmem_cache_cpu could be left alone even though it's a small saving
Its multiplied by the number of caches and by the number of
processors.
> o struct slab also be left alone
> o struct array_cache could be left alone although I would point out that
> it would make no difference in size as touched is changed to a bool to
> fit pfmemalloc in
Both of these are performance critical structures in slab.
> o It would still be necessary to do the object pointer tricks in slab.c
These trick are not done for slub. It seems that they are not necessary?
> remain. However, the downside of requiring a page flag is very high. In
> the event we increase the number of page flags - great, I'll use one but
> right now I do not think the use of page flag is justified.
On 64 bit I think there is not much of an issue with another page flag.
Also consider that the slab allocators do not make full use of the other
page flags. We could overload one of the existing flags. I removed
slubs use of them last year. PG_active could be overloaded I think.
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next prev parent reply other threads:[~2012-02-08 15:14 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-06 22:56 [PATCH 00/15] Swap-over-NBD without deadlocking V8 Mel Gorman
2012-02-06 22:56 ` [PATCH 01/15] mm: Serialize access to min_free_kbytes Mel Gorman
2012-02-08 18:47 ` Rik van Riel
2012-02-06 22:56 ` [PATCH 02/15] mm: sl[au]b: Add knowledge of PFMEMALLOC reserve pages Mel Gorman
2012-02-07 16:27 ` Christoph Lameter
2012-02-08 14:45 ` Mel Gorman
2012-02-08 15:14 ` Christoph Lameter [this message]
2012-02-08 16:34 ` Mel Gorman
2012-02-08 19:49 ` Christoph Lameter
2012-02-08 21:23 ` Mel Gorman
2012-02-08 22:13 ` Christoph Lameter
2012-02-09 12:50 ` Mel Gorman
2012-02-09 19:53 ` Christoph Lameter
2012-02-10 10:26 ` Mel Gorman
2012-02-10 21:01 ` Christoph Lameter
2012-02-10 22:07 ` Christoph Lameter
2012-02-13 10:12 ` Mel Gorman
2012-02-13 11:10 ` Mel Gorman
2012-02-06 22:56 ` [PATCH 03/15] mm: Introduce __GFP_MEMALLOC to allow access to emergency reserves Mel Gorman
2012-02-06 22:56 ` [PATCH 04/15] mm: allow PF_MEMALLOC from softirq context Mel Gorman
2012-02-06 22:56 ` [PATCH 05/15] mm: Ignore mempolicies when using ALLOC_NO_WATERMARK Mel Gorman
2012-02-06 22:56 ` [PATCH 06/15] net: Introduce sk_allocation() to allow addition of GFP flags depending on the individual socket Mel Gorman
2012-02-06 22:56 ` [PATCH 07/15] netvm: Allow the use of __GFP_MEMALLOC by specific sockets Mel Gorman
2012-02-06 22:56 ` [PATCH 08/15] netvm: Allow skb allocation to use PFMEMALLOC reserves Mel Gorman
2012-02-06 22:56 ` [PATCH 09/15] netvm: Propagate page->pfmemalloc to skb Mel Gorman
2012-02-06 22:56 ` [PATCH 10/15] netvm: Propagate page->pfmemalloc from netdev_alloc_page " Mel Gorman
2012-02-07 23:38 ` Alexander Duyck
2012-02-08 15:23 ` Mel Gorman
2012-02-06 22:56 ` [PATCH 11/15] netvm: Set PF_MEMALLOC as appropriate during SKB processing Mel Gorman
2012-02-06 22:56 ` [PATCH 12/15] mm: Micro-optimise slab to avoid a function call Mel Gorman
2012-02-06 22:56 ` [PATCH 13/15] nbd: Set SOCK_MEMALLOC for access to PFMEMALLOC reserves Mel Gorman
2012-02-06 22:56 ` [PATCH 14/15] mm: Throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage Mel Gorman
2012-02-06 22:56 ` [PATCH 15/15] mm: Account for the number of times direct reclaimers get throttled Mel Gorman
2012-02-07 12:45 ` [PATCH 00/15] Swap-over-NBD without deadlocking V8 Hillf Danton
2012-02-07 13:27 ` Mel Gorman
2012-02-08 12:51 ` Hillf Danton
2012-02-08 15:26 ` Mel Gorman
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