Re: drm/radeon spamming alloc_contig_range: [xxx, yyy) PFNs busy busy

[Vlastimil Babka]

On 12/01/2016 08:21 AM, Michal Hocko wrote:
> Forgot to CC Joonsoo. The email thread starts more or less here
> http://lkml.kernel.org/r/20161130092239.GD18437@xxxxxxxxxxxxxx
>
> On Thu 01-12-16 08:15:07, Michal Hocko wrote:
> > On Wed 30-11-16 20:19:03, Robin H. Johnson wrote:
> > [...]
> > > alloc_contig_range: [83f2a3, 83f2a4) PFNs busy
> >
> > Huh, do I get it right that the request was for a _single_ page? Why do
> > we need CMA for that?

Ugh, good point. I assumed that was just the PFNs that it failed to migrate 
away, but it seems that's indeed the whole requested range. Yeah sounds some 
part of the dma-cma chain could be smarter and attempt CMA only for e.g. costly 
orders.