From: Christoph Lameter <clameter@sgi.com>
To: David Miller <davem@davemloft.net>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-ia64@vger.kernel.org, torvalds@linux-foundation.org
Subject: Re: larger default page sizes...
Date: Tue, 25 Mar 2008 17:48:19 +0000 [thread overview]
Message-ID: <Pine.LNX.4.64.0803251045510.16206@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <20080324.144356.104645106.davem@davemloft.net>
On Mon, 24 Mar 2008, David Miller wrote:
> We should fix the underlying problems.
>
> I'm hitting issues on 128 cpu Niagara2 boxes, and it's all fundamental
> stuff like contention on the per-zone page allocator locks.
>
> Which is very fixable, without going to larger pages.
No its not fixable. You are doing linear optimizations to a slowdown that
grows exponentially. Going just one order up for page size reduces the
necessary locks and handling of the kernel by 50%.
> > powerpc also runs HPC codes. They certainly see the same results
> > that we see.
>
> There are ways to get large pages into the process address space for
> compute bound tasks, without suffering the well known negative side
> effects of using larger pages for everything.
These hacks have limitations. F.e. they do not deal with I/O and
require application changes.
next prev parent reply other threads:[~2008-03-25 17:48 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20080321061726.782068299@sgi.com>
[not found] ` <20080321.002502.223136918.davem@davemloft.net>
[not found] ` <Pine.LNX.4.64.0803211037140.18671@schroedinger.engr.sgi.com>
[not found] ` <20080321.145712.198736315.davem@davemloft.net>
2008-03-24 18:27 ` [11/14] vcompound: Fallbacks for order 1 stack allocations on Christoph Lameter
2008-03-24 20:37 ` larger default page sizes David Miller
2008-03-24 21:05 ` Christoph Lameter
2008-03-24 21:43 ` David Miller
2008-03-25 17:48 ` Christoph Lameter [this message]
2008-03-25 23:22 ` David Miller
2008-03-25 23:41 ` Peter Chubb
2008-03-25 23:49 ` David Miller
2008-03-26 0:25 ` Peter Chubb
2008-03-26 0:31 ` David Miller
2008-03-26 0:34 ` David Mosberger-Tang
2008-03-26 0:39 ` David Miller
2008-03-26 0:57 ` Peter Chubb
2008-03-26 4:16 ` John Marvin
2008-03-26 4:36 ` David Miller
2008-03-24 21:25 ` Luck, Tony
2008-03-24 21:46 ` David Miller
2008-03-25 3:29 ` Paul Mackerras
2008-03-25 4:15 ` David Miller
2008-03-25 11:50 ` Paul Mackerras
2008-03-25 23:32 ` David Miller
2008-03-25 23:49 ` Luck, Tony
2008-03-26 0:16 ` David Miller
2008-03-26 15:54 ` Nish Aravamudan
2008-03-26 17:05 ` Luck, Tony
2008-03-26 18:54 ` Mel Gorman
2008-03-25 12:05 ` Andi Kleen
2008-03-25 21:27 ` Paul Mackerras
2008-03-26 5:24 ` Paul Mackerras
2008-03-26 15:59 ` Linus Torvalds
2008-03-27 1:08 ` Paul Mackerras
2008-03-26 17:56 ` Christoph Lameter
2008-03-26 23:21 ` David Miller
2008-03-27 3:00 ` Paul Mackerras
2008-03-25 18:27 ` Dave Hansen
2008-03-24 21:13 ` [11/14] vcompound: Fallbacks for order 1 stack allocations on IA64 and x86 Luck, Tony
2008-03-25 17:42 ` [11/14] vcompound: Fallbacks for order 1 stack allocations on Christoph Lameter
2008-03-25 19:09 ` [11/14] vcompound: Fallbacks for order 1 stack allocations on IA64 and x86 Luck, Tony
2008-03-25 19:25 ` [11/14] vcompound: Fallbacks for order 1 stack allocations on Christoph Lameter
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