From: Dave Hansen <haveblue@us.ibm.com>
To: Andrea Arcangeli <andrea@suse.de>
Cc: David Chinner <dgc@sgi.com>,
linux-kernel@vger.kernel.org, David Kleikamp <shaggy@us.ibm.com>
Subject: Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)
Date: Thu, 12 Jul 2007 09:34:57 -0700 [thread overview]
Message-ID: <1184258097.26210.75.camel@localhost> (raw)
In-Reply-To: <20070712163123.GL28613@v2.random>
On Thu, 2007-07-12 at 18:31 +0200, Andrea Arcangeli wrote:
> On Fri, Jul 13, 2007 at 12:44:49AM +1000, David Chinner wrote:
> > That's crap. Just because a machine has lots of memory does not
> > make it OK to waste lots of memory.
>
> It's not just wasted, it lowers overhead all over the place. Yes, the
> benefit of wasting less pagecache may largely outweight the benefit of
> having a larger page size, but if you've a lot of memory perhaps your
> working set already fits in the cache, or perhaps you don't fit in the
> cache regardless of the page size.
Have you guys seen Shaggy's page cache tails?
http://kernel.org/pub/linux/kernel/people/shaggy/OLS-2006/kleikamp.pdf
We've had the same memory waste issue on ppc64 with 64k hardware
pages.
-- Dave
next prev parent reply other threads:[~2007-07-12 16:36 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-06 22:26 RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE) Andrea Arcangeli
2007-07-06 23:33 ` Dave Hansen
2007-07-06 23:52 ` Andrea Arcangeli
2007-07-17 17:47 ` William Lee Irwin III
2007-07-17 19:33 ` Andrea Arcangeli
2007-07-18 13:32 ` William Lee Irwin III
2007-07-18 16:34 ` Rene Herman
2007-07-18 23:50 ` Andrea Arcangeli
2007-07-19 0:53 ` Rene Herman
2007-07-24 19:44 ` Andrea Arcangeli
2007-07-25 3:20 ` William Lee Irwin III
2007-07-25 14:39 ` Andrea Arcangeli
2007-07-25 17:56 ` William Lee Irwin III
2007-07-07 1:36 ` Badari Pulavarty
2007-07-07 1:47 ` Badari Pulavarty
2007-07-07 10:12 ` Andrea Arcangeli
2007-07-07 7:01 ` Paul Mackerras
2007-07-07 10:25 ` Andrea Arcangeli
2007-07-07 18:53 ` Jan Engelhardt
2007-07-07 20:34 ` Rik van Riel
2007-07-08 9:52 ` Andrea Arcangeli
2007-07-08 23:20 ` David Chinner
2007-07-10 10:11 ` Andrea Arcangeli
2007-07-12 0:12 ` David Chinner
2007-07-12 11:14 ` Andrea Arcangeli
2007-07-12 14:44 ` David Chinner
2007-07-12 16:31 ` Andrea Arcangeli
2007-07-12 16:34 ` Dave Hansen [this message]
2007-07-13 7:13 ` David Chinner
2007-07-13 14:08 ` Dave Kleikamp
2007-07-13 14:31 ` Andrea Arcangeli
2007-07-16 0:27 ` David Chinner
2007-07-12 17:53 ` Matt Mackall
2007-07-13 1:06 ` Andrea Arcangeli
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