diff mbox series

[04/22] mm/hmm: support automatic NUMA balancing

Message ID 20190701062020.19239-5-hch@lst.de
State Not Applicable
Headers show
Series [01/22] mm/hmm.c: suppress compilation warnings when CONFIG_HUGETLB_PAGE is not set | expand

Commit Message

Christoph Hellwig July 1, 2019, 6:20 a.m. UTC 
From: Philip Yang <Philip.Yang@amd.com>

While the page is migrating by NUMA balancing, HMM failed to detect this
condition and still return the old page. Application will use the new page
migrated, but driver pass the old page physical address to GPU, this crash
the application later.

Use pte_protnone(pte) to return this condition and then hmm_vma_do_fault
will allocate new page.

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---
 mm/hmm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/mm/hmm.c b/mm/hmm.c
index 4db5dcf110ba..dce4e70e648a 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -548,7 +548,7 @@  static int hmm_vma_handle_pmd(struct mm_walk *walk,
 
 static inline uint64_t pte_to_hmm_pfn_flags(struct hmm_range *range, pte_t pte)
 {
-	if (pte_none(pte) || !pte_present(pte))
+	if (pte_none(pte) || !pte_present(pte) || pte_protnone(pte))
 		return 0;
 	return pte_write(pte) ? range->flags[HMM_PFN_VALID] |
 				range->flags[HMM_PFN_WRITE] :