From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Daniel Phillips <phillips@phunq.net>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
David Miller <davem@davemloft.net>,
Andrew Morton <akpm@linux-foundation.org>,
Daniel Phillips <phillips@google.com>,
Pekka Enberg <penberg@cs.helsinki.fi>,
Christoph Lameter <clameter@sgi.com>,
Matt Mackall <mpm@selenic.com>,
Lee Schermerhorn <Lee.Schermerhorn@hp.com>,
Steve Dickson <SteveD@redhat.com>
Subject: Re: [PATCH 00/10] foundations for reserve-based allocation
Date: Mon, 06 Aug 2007 21:36:58 +0200 [thread overview]
Message-ID: <1186429018.11797.100.camel@lappy> (raw)
In-Reply-To: <200708061231.04982.phillips@phunq.net>
On Mon, 2007-08-06 at 12:31 -0700, Daniel Phillips wrote:
> On Monday 06 August 2007 11:17, Peter Zijlstra wrote:
> > And how do we know a page was taken out of the reserves?
>
> Why not return that in the low bit of the page address? This is a
> little more cache efficient, does not leave that odd footprint in the
> page union and forces the caller to examine the
> alloc_pages(...P_MEMALLOC) return, making it harder to overlook the
> fact that it got a page out of reserve and forget to put one back
> later.
This would require auditing all page allocation sites to ensure they
ever happen under PF_MEMALLOC or the like. Because if an allocator ever
fails to check the low bit and assumes its a valid struct page *, stuff
will go *bang*.
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next prev parent reply other threads:[~2007-08-06 19:36 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-06 10:29 Peter Zijlstra
2007-08-06 10:29 ` [PATCH 01/10] mm: gfp_to_alloc_flags() Peter Zijlstra
2007-08-06 10:29 ` [PATCH 02/10] mm: system wide ALLOC_NO_WATERMARK Peter Zijlstra
2007-08-06 18:11 ` Christoph Lameter
2007-08-06 18:21 ` Daniel Phillips
2007-08-06 18:31 ` Peter Zijlstra
2007-08-06 18:43 ` Daniel Phillips
2007-08-06 19:11 ` Christoph Lameter
2007-08-06 19:31 ` Peter Zijlstra
2007-08-06 20:12 ` Christoph Lameter
2007-08-06 18:42 ` Christoph Lameter
2007-08-06 18:48 ` Daniel Phillips
2007-08-06 18:51 ` Christoph Lameter
2007-08-06 19:15 ` Daniel Phillips
2007-08-06 20:12 ` Matt Mackall
2007-08-06 20:19 ` Christoph Lameter
2007-08-06 20:26 ` Peter Zijlstra
2007-08-06 21:05 ` Christoph Lameter
2007-08-06 22:59 ` Daniel Phillips
2007-08-06 23:14 ` Christoph Lameter
2007-08-06 23:49 ` Daniel Phillips
2007-08-07 22:18 ` Christoph Lameter
2007-08-08 7:24 ` Peter Zijlstra
2007-08-08 18:06 ` Christoph Lameter
2007-08-08 7:37 ` Daniel Phillips
2007-08-08 18:09 ` Christoph Lameter
2007-08-09 18:41 ` Daniel Phillips
2007-08-09 18:49 ` Christoph Lameter
2007-08-10 0:17 ` Daniel Phillips
2007-08-10 1:48 ` Christoph Lameter
2007-08-10 3:34 ` Daniel Phillips
2007-08-10 3:48 ` Christoph Lameter
2007-08-10 8:15 ` Daniel Phillips
2007-08-10 17:46 ` Christoph Lameter
2007-08-10 23:25 ` Daniel Phillips
2007-08-13 6:55 ` Daniel Phillips
2007-08-13 23:04 ` Christoph Lameter
2007-08-06 20:27 ` Andrew Morton
2007-08-06 23:16 ` Daniel Phillips
2007-08-06 22:47 ` Daniel Phillips
2007-08-06 10:29 ` [PATCH 03/10] mm: tag reseve pages Peter Zijlstra
2007-08-06 18:11 ` Christoph Lameter
2007-08-06 18:13 ` Daniel Phillips
2007-08-06 18:28 ` Peter Zijlstra
2007-08-06 19:34 ` Andi Kleen
2007-08-06 18:43 ` Christoph Lameter
2007-08-06 18:47 ` Peter Zijlstra
2007-08-06 18:59 ` Andi Kleen
2007-08-06 19:09 ` Christoph Lameter
2007-08-06 19:10 ` Andrew Morton
2007-08-06 19:16 ` Christoph Lameter
2007-08-06 19:38 ` Matt Mackall
2007-08-06 20:18 ` Andi Kleen
2007-08-06 10:29 ` [PATCH 04/10] mm: slub: add knowledge of reserve pages Peter Zijlstra
2007-08-08 0:13 ` Christoph Lameter
2007-08-08 1:44 ` Matt Mackall
2007-08-08 17:13 ` Christoph Lameter
2007-08-08 17:39 ` Andrew Morton
2007-08-08 17:57 ` Christoph Lameter
2007-08-08 18:46 ` Andrew Morton
2007-08-10 1:54 ` Daniel Phillips
2007-08-10 2:01 ` Christoph Lameter
2007-08-20 7:38 ` Peter Zijlstra
2007-08-20 7:43 ` Peter Zijlstra
2007-08-20 9:12 ` Pekka J Enberg
2007-08-20 9:17 ` Peter Zijlstra
2007-08-20 9:28 ` Pekka Enberg
2007-08-20 19:26 ` Christoph Lameter
2007-08-20 20:08 ` Peter Zijlstra
2007-08-06 10:29 ` [PATCH 05/10] mm: allow mempool to fall back to memalloc reserves Peter Zijlstra
2007-08-06 10:29 ` [PATCH 06/10] mm: kmem_estimate_pages() Peter Zijlstra
2007-08-06 10:29 ` [PATCH 07/10] mm: allow PF_MEMALLOC from softirq context Peter Zijlstra
2007-08-06 10:29 ` [PATCH 08/10] mm: serialize access to min_free_kbytes Peter Zijlstra
2007-08-06 10:29 ` [PATCH 09/10] mm: emergency pool Peter Zijlstra
2007-08-06 10:29 ` [PATCH 10/10] mm: __GFP_MEMALLOC Peter Zijlstra
2007-08-06 17:35 ` [PATCH 00/10] foundations for reserve-based allocation Daniel Phillips
2007-08-06 18:17 ` Peter Zijlstra
2007-08-06 18:40 ` Daniel Phillips
2007-08-06 19:31 ` Daniel Phillips
2007-08-06 19:36 ` Peter Zijlstra [this message]
2007-08-06 19:53 ` Daniel Phillips
2007-08-06 17:56 ` Christoph Lameter
2007-08-06 18:33 ` Peter Zijlstra
2007-08-06 20:23 ` Matt Mackall
2007-08-07 0:09 ` Daniel Phillips
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