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SubjectRe: spin_lock forgets to clobber memory and other smp fixes [was
kuznet@ms2.inr.ac.ru wrote:
> Just hint. I remember the time when "memory" clobber option
> was _absent_ in gcc. And we managed to compile kernel with such gcc. 8)
> To all that I understand, "asm" (like function calls) implied barrier
> that time and constraints and clobber option were used only for
> register allocation and reloading.

Well, now GCC does CSE across "asm" and will eliminate memory loads,
even though it may not move them! I suspect it always did CSE across
"asm" and we just never got hit by the bug.

-- Jamie
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