[PATCH] powerpc: POWER7 optimised copy_to_user/copy_from_user using VMX

Segher Boessenkool segher at kernel.crashing.org
Fri Dec 9 01:12:26 EST 2011


>>> 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



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