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From: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [PATCH] powerpc: POWER7 optimised copy_to_user/copy_from_user
 using VMX
Date: Thu, 8 Dec 2011 15:12:26 +0100
To: "David Laight" <David.Laight@ACULAB.COM>
Cc: paulus@samba.org, Michael Neuling <mikey@neuling.org>,
 sukadev@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org,
 Anton Blanchard <anton@samba.org>
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>>> One idea would be to have a structure of function pointers for each
>>> CPU that gets runtime patched into the right places,
>>> similar to how we do some of the MMU fixups.
>>
>> Sounds good to me :-)
>
> Except the indirect jump/call is almost certainly
> never predicted - so will be slow.

What indirect jump?  He said "runtime patched" :-)

Also, that "slow" is largely a myth.


Segher