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-rw-r--r--mm/migrate.c44
1 files changed, 25 insertions, 19 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 84381b55b2bd..b6700f2962f3 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -685,6 +685,8 @@ void migrate_page_states(struct page *newpage, struct page *page)
SetPageActive(newpage);
} else if (TestClearPageUnevictable(page))
SetPageUnevictable(newpage);
+ if (PageWorkingset(page))
+ SetPageWorkingset(newpage);
if (PageChecked(page))
SetPageChecked(newpage);
if (PageMappedToDisk(page))
@@ -1973,8 +1975,7 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
int isolated = 0;
struct page *new_page = NULL;
int page_lru = page_is_file_cache(page);
- unsigned long mmun_start = address & HPAGE_PMD_MASK;
- unsigned long mmun_end = mmun_start + HPAGE_PMD_SIZE;
+ unsigned long start = address & HPAGE_PMD_MASK;
new_page = alloc_pages_node(node,
(GFP_TRANSHUGE_LIGHT | __GFP_THISNODE),
@@ -1997,15 +1998,15 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
/* anon mapping, we can simply copy page->mapping to the new page: */
new_page->mapping = page->mapping;
new_page->index = page->index;
+ /* flush the cache before copying using the kernel virtual address */
+ flush_cache_range(vma, start, start + HPAGE_PMD_SIZE);
migrate_page_copy(new_page, page);
WARN_ON(PageLRU(new_page));
/* Recheck the target PMD */
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
ptl = pmd_lock(mm, pmd);
if (unlikely(!pmd_same(*pmd, entry) || !page_ref_freeze(page, 2))) {
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
/* Reverse changes made by migrate_page_copy() */
if (TestClearPageActive(new_page))
@@ -2029,16 +2030,26 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
/*
- * Clear the old entry under pagetable lock and establish the new PTE.
- * Any parallel GUP will either observe the old page blocking on the
- * page lock, block on the page table lock or observe the new page.
- * The SetPageUptodate on the new page and page_add_new_anon_rmap
- * guarantee the copy is visible before the pagetable update.
+ * Overwrite the old entry under pagetable lock and establish
+ * the new PTE. Any parallel GUP will either observe the old
+ * page blocking on the page lock, block on the page table
+ * lock or observe the new page. The SetPageUptodate on the
+ * new page and page_add_new_anon_rmap guarantee the copy is
+ * visible before the pagetable update.
*/
- flush_cache_range(vma, mmun_start, mmun_end);
- page_add_anon_rmap(new_page, vma, mmun_start, true);
- pmdp_huge_clear_flush_notify(vma, mmun_start, pmd);
- set_pmd_at(mm, mmun_start, pmd, entry);
+ page_add_anon_rmap(new_page, vma, start, true);
+ /*
+ * At this point the pmd is numa/protnone (i.e. non present) and the TLB
+ * has already been flushed globally. So no TLB can be currently
+ * caching this non present pmd mapping. There's no need to clear the
+ * pmd before doing set_pmd_at(), nor to flush the TLB after
+ * set_pmd_at(). Clearing the pmd here would introduce a race
+ * condition against MADV_DONTNEED, because MADV_DONTNEED only holds the
+ * mmap_sem for reading. If the pmd is set to NULL at any given time,
+ * MADV_DONTNEED won't wait on the pmd lock and it'll skip clearing this
+ * pmd.
+ */
+ set_pmd_at(mm, start, pmd, entry);
update_mmu_cache_pmd(vma, address, &entry);
page_ref_unfreeze(page, 2);
@@ -2047,11 +2058,6 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
set_page_owner_migrate_reason(new_page, MR_NUMA_MISPLACED);
spin_unlock(ptl);
- /*
- * No need to double call mmu_notifier->invalidate_range() callback as
- * the above pmdp_huge_clear_flush_notify() did already call it.
- */
- mmu_notifier_invalidate_range_only_end(mm, mmun_start, mmun_end);
/* Take an "isolate" reference and put new page on the LRU. */
get_page(new_page);
@@ -2075,7 +2081,7 @@ out_fail:
ptl = pmd_lock(mm, pmd);
if (pmd_same(*pmd, entry)) {
entry = pmd_modify(entry, vma->vm_page_prot);
- set_pmd_at(mm, mmun_start, pmd, entry);
+ set_pmd_at(mm, start, pmd, entry);
update_mmu_cache_pmd(vma, address, &entry);
}
spin_unlock(ptl);