[PATCH] i386: pte xchg optimization

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In situations where page table updates need only be made locally, and there is
no cross-processor A/D bit races involved, we need not use the heavyweight
xchg instruction to atomically fetch and clear page table entries.  Instead,
we can just read and clear them directly.

This introduces a neat optimization for non-SMP kernels; drop the atomic xchg
operations from page table updates.

Thanks to Michel Lespinasse for noting this potential optimization.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>

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Zachary Amsden 2007-05-02 19:27:19 +02:00 • committed by Andi Kleen

parent c2c1accd4b

commit 142dd97591

2 changed files with 28 additions and 0 deletions

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14

include/asm-i386/pgtable-2level.h

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14

include/asm-i386/pgtable-3level.h

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