Re: [patch] x86, mm: pass in 'total' to __copy_from_user_*nocache()

From: Andi Kleen
Date: Sat Feb 28 2009 - 13:07:28 EST


Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:

> That's almost unacceptable in the long run. With a 8MB L3 cache - and a
> compile sequence, do we really want to go out to memory to write the .S
> file, and then have the assembler go out to memory to read it back? For

One possible way would be to make the threshold dependent on the LLC
cache size, so that let's say an Atom still prefers to not pollute
its caches. But I agree with you that it's probably better to
just drop the nocache copies completely.

-Andi

--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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