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	Fri, 17 Jun 2011 15:58:26 +1000 (EST)
Subject: Re: [PATCH 3/3] powerpc: POWER7 optimised
	copy_to_user/copy_from_user using VMX
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Anton Blanchard <anton@samba.org>
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Date: Fri, 17 Jun 2011 15:58:20 +1000
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On Fri, 2011-06-17 at 14:54 +1000, Anton Blanchard wrote:
> plain text document attachment (power7_copy_tofrom_user)
> Implement a POWER7 optimised copy_to_user/copy_from_user using VMX.
> For large aligned copies this new loop is over 10% faster, and for
> large unaligned copies it is over 200% faster.
> 
> If we take a fault we fall back to the old version, this keeps
> things relatively simple and easy to verify.

Same re-entrancy comment as the other ones. preempt & interrupts...
Except here is worse since you may page fault and thus lose the vmx
state completely.

Cheers,
Ben.