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Date: Mon, 17 Mar 2003 07:10:04 -0800
From: William Lee Irwin III <wli@holomorphy.com>
To: Rik van Riel <riel@surriel.com>
Cc: Paul Albrecht <palbrecht@uswest.net>, linux-kernel@vger.kernel.org
Subject: Re: 2.4 vm, program load, page faulting, ...
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On Sat, 15 Mar 2003, Paul Albrecht wrote:
>> ... Why does the kernel page fault on text pages, present in the page
>> cache, when a program starts? Couldn't the pte's for text present in the
>> page cache be resolved when they're mapped to memory?

On Mon, Mar 17, 2003 at 10:02:21AM -0500, Rik van Riel wrote:
> The mmap() syscall only sets up the VMA info, it doesn't
> fill in the page tables. That only happens when the process
> page faults.
> Note that filling in a bunch of page table entries mapping
> already present pagecache pages at exec() time might be a
> good idea.  It's just that nobody has gotten around to that
> yet...

SVR4 did and saw an improvement wrt. page fault rate, according to
Vahalia.

I'd like to see whether this is useful for Linux.


-- wli
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