Re: [PATCH 10/11] x86, rwsem: provide __down_write_killable

Borislav Petkov
2016-04-20T21:36:37Z

On Wed, Apr 20, 2016 at 02:06:33PM -0700, H. Peter Anvin wrote:
> Setting ret to sem doesn't make any sense. Just use "=a" and "a".

Yeah, that's what Michal's patch ontop does.

And to answer my own question: we need the "a" (sem) input for the fast
path.

I guess we can still move "1" (RWSEM_ACTIVE_WRITE_BIAS) before the asm():

long tmp = RWSEM_ACTIVE_WRITE_BIAS;

One thing I'm still not clear on is why we need the output tmp operand:
"=d" (tmp) ?

--
Regards/Gruss,
Boris.

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