Hi Dan, On Mon, Nov 14, 2016 at 07:14:22PM -0800, Dan Williams wrote: > Wanted to get your opinion on this given your earlier concerns about > the VM_DAX flag. > > This instead lets an application know how much of a vma is backed by > ZONE_DEVICE pages, but does not make any indications about the vma > having DAX semantics or not. I.e. it is possible that 'device' and > 'device_huge' are non-zero *and* vma_is_dax() is false. So, it is > purely accounting the composition of the present pages in the vma. > > Another option is to have something like 'shared_thp' just to account > for file backed huge pages that dax can map. However if ZONE_DEVICE > is leaking into other use cases I think it makes sense to have it be a > first class-citizen with respect to accounting alongside > 'anonymous_thp'. This counter sounds fine to me, it's a debug tool and not an obvious abuse candidate like VM_DAX. But I'll defer to the VM folks for a real review. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>