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

[Vlastimil Babka]

On 12/01/2016 10:02 PM, Michal Nazarewicz wrote:
> On Thu, Dec 01 2016, Michal Hocko wrote:
> > I am not familiar with this code so I cannot really argue but a quick
> > look at rmem_cma_setup doesn't suggest any speicific placing or
> > anything...
>
> early_cma parses âcmaâ command line argument which can specify where
> exactly the default CMA area is to be located.  Furthermore, CMA areas
> can be assigned per-device (via the Device Tree IIRC).

OK, but the context of this bug report is a generic cma pool and generic 
dma alloc, which tries cma first and then fallback to 
alloc_pages_node(). If a device really requires specific placing as you 
suggest, then it probably uses a different allocation interface, 
otherwise there would be some flag to disallow the alloc_pages_node() 
fallback?