Re: [PATCH v4 3/3] qspinlock, x86: Add x86 specific optimization for 2 contending tasks

[Peter Zijlstra]

On Fri, Feb 21, 2014 at 12:09:57PM -0500, Waiman Long wrote:
> On 02/21/2014 12:08 PM, Waiman Long wrote:
> >On 02/21/2014 07:12 AM, Peter Zijlstra wrote:
> >>
> >>Why is this x86 only code?
> >
> >The code is making use of the fact that byte write is atomic which is true
> >in x86 and probably in a few other architectures. I could pull these codes
> >into the generic qspinlock.c file and set a flag in the asm header file to
> >activate it if it is what you want.
> >
> >-Longman
> 
> BTW, I also assume that 8-bit and 16-bit cmpxchg() and xchg() are available.

Right, screw Alpha :-) Just pull it into the generic code; its far too
much code to replicate per arch.
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