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SubjectRe: [patch 1/2] i386: use asm() like the other atomic operations already do.
Herbert Xu wrote:
> Andi Kleen <ak@suse.de> wrote:
>>> My config with march=pentium-m and gcc (GCC) 4.1.2 (Gentoo 4.1.2):
>>> text data bss dec hex filename
>>> 3434150 249176 176128 3859454 3ae3fe atomic_normal/vmlinux
>>> 3435308 249176 176128 3860612 3ae884 atomic_inlineasm/vmlinux
>> What is the difference between atomic_normal and atomic_inlineasm?
>
> The inline asm stops certain optimisations from occuring.
>
> I'm still unconvinced why we need this because nobody has
> brought up any examples of kernel code that legitimately
> need this.

There's plenty of kernel code that *wants* this though. If we can
reduce the need for register-clobbering barriers, shrink our binaries,
shrink our code, improve performance, and avoid heisenbugs, I think it's
a win, whether or not we *need* it.

-- Chris
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