On 08/19/22 18:12, Baolin Wang wrote: > Hi, > > On ARM64 architecture, it can support CONT-PTE/PMD size hugetlb. When > looking up hugetlb page by follow_page(), we will hold the incorrect > pte/pmd lock for the CONT-PTE/PMD size hugetlb page, which will make > the pte/pmd entry unstable even under the lock and cause some potential > race issues. So considering the CONT-PTE/PMD size hugetlb, this patch set > changes to use the correct function to get the correct pte/pmd entry lock > to make the pte/pmd entry stable. Thank you for looking at this. I often get confused by arm64 CONT-PTE/PMD layout, so my understanding may be wrong. Can we use the PMD page lock for locking both CONT-PTE and CONT-PMD entries? Again, I may be confused by the CONT-* page table layout, but it seems these would all be referenced via that same PMD page of the page table. Or, perhaps CONT-PMD can span multiple PMD pages? If we can use PMD page for locking, this would be much finer grain that lock in the mm. -- Mike Kravetz
