On Mon, Mar 16, 2020 at 08:32:15PM +0100, Christoph Hellwig wrote:

diff --git a/mm/hmm.c b/mm/hmm.c index 180e398170b0..cfad65f6a67b 100644 +++ b/mm/hmm.c @@ -118,15 +118,6 @@ static inline void hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk, /* We aren't ask to do anything ... */ if (!(pfns & range->flags[HMM_PFN_VALID])) return;

• /* If this is device memory then only fault if explicitly requested */
• if ((cpu_flags & range->flags[HMM_PFN_DEVICE_PRIVATE])) {

• /* Do we fault on device memory ? */
  

• if (pfns & range->flags[HMM_PFN_DEVICE_PRIVATE]) {
  

• 	*write_fault = pfns & range->flags[HMM_PFN_WRITE];
  

• 	*fault = true;
  

• }
  

• return;
  

• }

Yes, this is an elegant solution to the input flags.

However, between patch 3 and 4 doesn't this break amd gpu as it will return device_private pages now if not requested? Squash the two?

Jason