[ofa-general] [PATCH] IB/mlx4: Use pgprot_writecombine() for BlueFlame pages

[Or Gerlitz]

Roland Dreier wrote:
>
> I don't understand: your results below don't seem to have good results 
> without X86_PAT?  In any case I don't see how you can get the lowest 
> latency (from WC mapping to userspace) without X86_PAT, since 
> pgprot_writecombine() will fall back to pgprot_noncached() is X86_PAT=n.
>
Again, the facts are that on my latest round of testing I got a latency 
of 1.4us with and without X86_PAT which went down to 1.1us when applying 
your patch on top of a X86_PAT config. Even if I'm doing something 
wrong, I still want to see that we understand each other... so please 
let me know if you still don't understand me.

Or.