Re: [PATCH] bitops: add _local bitops

H. Peter Anvin
2012-05-09T20:10:04Z

On 05/09/2012 01:07 PM, Michael S. Tsirkin wrote:
>
> In practice ATM any of the above will work. We probably don't even need
> to add barrier() calls since what we do afterwards is apic access which
> has an optimization barrier anyway. But I'm fine with adding them in
> there just in case if that's what people want.
>

If you have the optimization barrier anyway, then I'd be fine with you
just using __test_and_clear_bit() and add to a comment in
arch/x86/include/asm/bitops.h that KVM needs it to be locally atomic.

-hpa