+ *
+ * If that does not hold for an architecture, then that architecture
+ * must disable split PT locks such that all *_lockptr() functions
+ * will give us the same result: the per-MM PT lock.
+ */
+ if (huge_page_size(h) < PMD_SIZE)
+ return pte_lockptr(mm, pte);
+ else if (huge_page_size(h) < PUD_SIZE)
return pmd_lockptr(mm, (pmd_t *) pte);
IIUC, as I said above, this change doesn't fix the inconsistent lock for
cont-PMD size hugetlb for GUP, and it will also break the lock rule for
unmapping/migrating a cont-PMD size hugetlb (use mm->page_table_lock
before for cont-PMD size hugetlb before).
After more thinking, I realized I confused the PMD table with the PMD
entry. Therefore, using the PMD table's lock is safe for cont-PMD size
hugetlb. This change looks good to me. Sorry for noise.
Thanks for the review, highly appreciated!
--
Cheers,
David / dhildenb
