[openib-general] [PATCH] use mmiowb after doorbell ring

[Michael S. Tsirkin]

Quoting r. Roland Dreier <rdreier at cisco.com>:
>  > as for mb() - I don't thnk our kernel code uses that so I think userspace
>  > should switch to wmb as well. wmb isjust a compiler barrier on most
>  > arhitectures.
> 
> I'm not sure it's worth the trouble to split up the two cases at this
> point.

Shouldn't be hard - just look at kernel code and make userspac to match.

> Does it make a bit performance difference?

I imagine it does, latency-wise.

-- 
MST