From: Andrew Morton <akpm@linux-foundation.org>
To: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>, Hugh Dickins <hughd@google.com>,
linux-kernel@vger.kernel.org,
Russell King <linux@arm.linux.org.uk>,
Ralf Baechle <ralf@linux-mips.org>,
Paul Mundt <lethal@linux-sh.org>,
"David S. Miller" <davem@davemloft.net>,
Chris Metcalf <cmetcalf@tilera.com>,
x86@kernel.org, William Irwin <wli@holomorphy.com>,
linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org,
linux-mips@linux-mips.org, linux-sh@vger.kernel.org,
sparclinux@vger.kernel.org
Subject: Re: [PATCH 07/16] mm: fix cache coloring on x86_64 architecture
Date: Tue, 6 Nov 2012 14:38:19 -0800 [thread overview]
Message-ID: <20121106143819.4309031c.akpm@linux-foundation.org> (raw)
In-Reply-To: <1352155633-8648-8-git-send-email-walken@google.com>
On Mon, 5 Nov 2012 14:47:04 -0800
Michel Lespinasse <walken@google.com> wrote:
> Fix the x86-64 cache alignment code to take pgoff into account.
> Use the x86 and MIPS cache alignment code as the basis for a generic
> cache alignment function.
>
> The old x86 code will always align the mmap to aliasing boundaries,
> even if the program mmaps the file with a non-zero pgoff.
>
> If program A mmaps the file with pgoff 0, and program B mmaps the
> file with pgoff 1. The old code would align the mmaps, resulting in
> misaligned pages:
>
> A: 0123
> B: 123
>
> After this patch, they are aligned so the pages line up:
>
> A: 0123
> B: 123
We have a bit of a history of fiddling with coloring and finding that
the changes made at best no improvement. Or at least, that's my
perhaps faulty memory of it.
This one needs pretty careful testing, please.
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next prev parent reply other threads:[~2012-11-06 22:38 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-05 22:46 [PATCH 00/16] mm: use augmented rbtrees for finding unmapped areas Michel Lespinasse
2012-11-05 22:46 ` [PATCH 01/16] mm: add anon_vma_lock to validate_mm() Michel Lespinasse
2012-11-05 23:06 ` Rik van Riel
2012-11-06 8:00 ` Michel Lespinasse
2012-11-05 22:46 ` [PATCH 02/16] mm: augment vma rbtree with rb_subtree_gap Michel Lespinasse
2012-11-05 22:47 ` [PATCH 03/16] mm: check rb_subtree_gap correctness Michel Lespinasse
2012-11-06 22:38 ` Andrew Morton
2012-11-09 14:13 ` Sasha Levin
2012-11-09 20:06 ` Hugh Dickins
2012-11-12 11:55 ` Michel Lespinasse
2012-11-05 22:47 ` [PATCH 04/16] mm: rearrange vm_area_struct for fewer cache misses Michel Lespinasse
2012-11-05 22:47 ` [PATCH 05/16] mm: vm_unmapped_area() lookup function Michel Lespinasse
2012-11-05 22:47 ` [PATCH 06/16] mm: use vm_unmapped_area() on x86_64 architecture Michel Lespinasse
2012-11-05 22:47 ` [PATCH 07/16] mm: fix cache coloring " Michel Lespinasse
2012-11-06 22:38 ` Andrew Morton [this message]
2012-11-05 22:47 ` [PATCH 08/16] mm: use vm_unmapped_area() in hugetlbfs Michel Lespinasse
2012-11-05 23:33 ` Rik van Riel
2012-11-05 22:47 ` [PATCH 09/16] mm: use vm_unmapped_area() in hugetlbfs on i386 architecture Michel Lespinasse
2012-11-05 23:07 ` Rik van Riel
2012-11-06 22:38 ` Andrew Morton
2012-11-06 22:48 ` Rik van Riel
2012-11-05 22:47 ` [PATCH 10/16] mm: use vm_unmapped_area() on mips architecture Michel Lespinasse
2012-11-05 23:34 ` Rik van Riel
2012-11-06 22:38 ` Andrew Morton
2012-11-05 22:47 ` [PATCH 11/16] mm: use vm_unmapped_area() on arm architecture Michel Lespinasse
2012-11-05 23:35 ` Rik van Riel
2012-11-06 22:38 ` Andrew Morton
2012-11-05 22:47 ` [PATCH 12/16] mm: use vm_unmapped_area() on sh architecture Michel Lespinasse
2012-11-05 23:35 ` Rik van Riel
2012-11-05 22:47 ` [PATCH 13/16] mm: use vm_unmapped_area() on sparc64 architecture Michel Lespinasse
2012-11-05 23:36 ` Rik van Riel
2012-11-05 22:47 ` [PATCH 14/16] mm: use vm_unmapped_area() in hugetlbfs " Michel Lespinasse
2012-11-05 23:36 ` Rik van Riel
2012-11-05 22:47 ` [PATCH 15/16] mm: use vm_unmapped_area() on sparc32 architecture Michel Lespinasse
2012-11-05 23:37 ` Rik van Riel
2012-11-06 1:25 ` David Miller
2012-11-06 3:13 ` Michel Lespinasse
2012-11-06 7:30 ` Rik van Riel
2012-11-06 17:41 ` David Miller
2012-11-05 22:47 ` [PATCH 16/16] mm: use vm_unmapped_area() in hugetlbfs on tile architecture Michel Lespinasse
2012-11-05 23:37 ` Rik van Riel
2012-11-06 22:11 ` [PATCH 00/16] mm: use augmented rbtrees for finding unmapped areas Andrew Morton
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