Re: [RFC][PATCH 6/8] mm: handle_speculative_fault()

From: Andi Kleen
Date: Tue Jan 05 2010 - 12:25:45 EST


Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:
>
> etc, because the x86-64 code has obviously never seen the optimized
> call-paths, and they need the asm wrappers for full semantics.

iirc Andrea ran benchmarks at some point and it didn't make too much
difference on the systems back then (K8 era). Given K8 has fast atomics.

> Oh well. Somebody who is bored might look at trying to make the wrapper
> code in arch/x86/lib/semaphore_32.S work on x86-64 too. It should make the
> successful rwsem cases much faster.

Maybe, maybe not.

-Andi

--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/