Re: [PATCH v4 5/5] x86: drop mfence in favor of lock+addl
From: Michael S. Tsirkin
Date: Wed Jan 27 2016 - 12:56:49 EST
On Wed, Jan 27, 2016 at 09:37:45AM -0800, Linus Torvalds wrote:
> On Wed, Jan 27, 2016 at 7:10 AM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> > -#define __smp_mb() mb()
> > +#define __smp_mb() asm volatile("lock; addl $0,-4(%%esp)" ::: "memory", "cc")
> So this doesn't look right for x86-64. Using %esp rather than %rsp.
> How did that even work for you?
Oops, didn't test this version properly.
Pls disregard, I'll repost after some proper testing.