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 at dhcp22.suse.cz > > 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.
