diff options
author | Yang, Philip <Philip.Yang@amd.com> | 2019-08-15 22:52:56 +0200 |
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committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-23 15:22:20 +0200 |
commit | e3fe8e555dd05cf74168d18555c44320ed50a0e1 (patch) | |
tree | 93a7d05212b8be9eabffd7ecb0b4358f061c2293 /mm/hmm.c | |
parent | mm/mmu_notifiers: remove unregister_no_release (diff) | |
download | linux-e3fe8e555dd05cf74168d18555c44320ed50a0e1.tar.xz linux-e3fe8e555dd05cf74168d18555c44320ed50a0e1.zip |
mm/hmm: fix hmm_range_fault()'s handling of swapped out pages
hmm_range_fault() may return NULL pages because some of the pfns are equal
to HMM_PFN_NONE. This happens randomly under memory pressure. The reason
is during the swapped out page pte path, hmm_vma_handle_pte() doesn't
update the fault variable from cpu_flags, so it failed to call
hmm_vam_do_fault() to swap the page in.
The fix is to call hmm_pte_need_fault() to update fault variable.
Fixes: 74eee180b935 ("mm/hmm/mirror: device page fault handler")
Link: https://lore.kernel.org/r/20190815205227.7949-1-Philip.Yang@amd.com
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: "Jérôme Glisse" <jglisse@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'mm/hmm.c')
-rw-r--r-- | mm/hmm.c | 3 |
1 files changed, 3 insertions, 0 deletions
@@ -469,6 +469,9 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, swp_entry_t entry = pte_to_swp_entry(pte); if (!non_swap_entry(entry)) { + cpu_flags = pte_to_hmm_pfn_flags(range, pte); + hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, + &fault, &write_fault); if (fault || write_fault) goto fault; return 0; |