ret = 0;
goto out_unlock;
}
+
if (unlikely(pmd_trans_splitting(pmd))) {
/* split huge page running from under us */
spin_unlock(src_ptl);
if (unlikely(!pmd_same(pmd, *pmdp)))
goto out_unlock;
+ /*
+ * If there are potential migrations, wait for completion and retry
+ * without disrupting NUMA hinting information. Do not relock and
+ * check_same as the page may no longer be mapped.
+ */
+ if (unlikely(pmd_trans_migrating(*pmdp))) {
+ spin_unlock(ptl);
+ wait_migrate_huge_page(vma->anon_vma, pmdp);
+ goto out;
+ }
+
page = pmd_page(pmd);
BUG_ON(is_huge_zero_page(page));
page_nid = page_to_nid(page);
goto clear_pmdnuma;
}
- /*
- * If there are potential migrations, wait for completion and retry. We
- * do not relock and check_same as the page may no longer be mapped.
- * Furtermore, even if the page is currently misplaced, there is no
- * guarantee it is still misplaced after the migration completes.
- */
+ /* Migration could have started since the pmd_trans_migrating check */
if (!page_locked) {
spin_unlock(ptl);
wait_on_page_locked(page);
ret = 1;
if (!prot_numa) {
entry = pmdp_get_and_clear(mm, addr, pmd);
+ if (pmd_numa(entry))
+ entry = pmd_mknonnuma(entry);
entry = pmd_modify(entry, newprot);
ret = HPAGE_PMD_NR;
BUG_ON(pmd_write(entry));