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Diffstat (limited to 'mm/khugepaged.c')
-rw-r--r--mm/khugepaged.c35
1 files changed, 20 insertions, 15 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 0a1b4b484ac5..a8a57bebb5fa 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1028,12 +1028,13 @@ static void collapse_huge_page(struct mm_struct *mm,
anon_vma_lock_write(vma->anon_vma);
- pte = pte_offset_map(pmd, address);
- pte_ptl = pte_lockptr(mm, pmd);
-
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, NULL, mm,
address, address + HPAGE_PMD_SIZE);
mmu_notifier_invalidate_range_start(&range);
+
+ pte = pte_offset_map(pmd, address);
+ pte_ptl = pte_lockptr(mm, pmd);
+
pmd_ptl = pmd_lock(mm, pmd); /* probably unnecessary */
/*
* After this gup_fast can't run anymore. This also removes
@@ -1601,17 +1602,6 @@ static void collapse_file(struct mm_struct *mm,
result = SCAN_FAIL;
goto xa_unlocked;
}
- } else if (!PageUptodate(page)) {
- xas_unlock_irq(&xas);
- wait_on_page_locked(page);
- if (!trylock_page(page)) {
- result = SCAN_PAGE_LOCK;
- goto xa_unlocked;
- }
- get_page(page);
- } else if (PageDirty(page)) {
- result = SCAN_FAIL;
- goto xa_locked;
} else if (trylock_page(page)) {
get_page(page);
xas_unlock_irq(&xas);
@@ -1626,7 +1616,12 @@ static void collapse_file(struct mm_struct *mm,
* without racing with truncate.
*/
VM_BUG_ON_PAGE(!PageLocked(page), page);
- VM_BUG_ON_PAGE(!PageUptodate(page), page);
+
+ /* make sure the page is up to date */
+ if (unlikely(!PageUptodate(page))) {
+ result = SCAN_FAIL;
+ goto out_unlock;
+ }
/*
* If file was truncated then extended, or hole-punched, before
@@ -1642,6 +1637,16 @@ static void collapse_file(struct mm_struct *mm,
goto out_unlock;
}
+ if (!is_shmem && PageDirty(page)) {
+ /*
+ * khugepaged only works on read-only fd, so this
+ * page is dirty because it hasn't been flushed
+ * since first write.
+ */
+ result = SCAN_FAIL;
+ goto out_unlock;
+ }
+
if (isolate_lru_page(page)) {
result = SCAN_DEL_PAGE_LRU;
goto out_unlock;