@@ -1838,26 +1838,29 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
while (!list_empty(list)) {
page = lru_to_page(list);
VM_BUG_ON_PAGE(PageLRU(page), page);
+ list_del(&page->lru);
if (unlikely(!page_evictable(page))) {
- list_del(&page->lru);
spin_unlock_irq(&pgdat->lru_lock);
putback_lru_page(page);
spin_lock_irq(&pgdat->lru_lock);
continue;
}
- lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ /*
+ * The SetPageLRU needs to be kept here for list intergrity.
+ * Otherwise:
+ * #0 mave_pages_to_lru #1 release_pages
+ * if (put_page_testzero())
+ * if !put_page_testzero
+ * !PageLRU //skip lru_lock
+ * list_add(&page->lru,)
+ * list_add(&page->lru,) //corrupt
+ */
SetPageLRU(page);
- lru = page_lru(page);
-
- nr_pages = hpage_nr_pages(page);
- update_lru_size(lruvec, lru, page_zonenum(page), nr_pages);
- list_move(&page->lru, &lruvec->lists[lru]);
- if (put_page_testzero(page)) {
+ if (unlikely(put_page_testzero(page))) {
__ClearPageLRU(page);
__ClearPageActive(page);
- del_page_from_lru_list(page, lruvec, lru);
if (unlikely(PageCompound(page))) {
spin_unlock_irq(&pgdat->lru_lock);
@@ -1865,9 +1868,16 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
spin_lock_irq(&pgdat->lru_lock);
} else
list_add(&page->lru, &pages_to_free);
- } else {
- nr_moved += nr_pages;
+ continue;
}
+
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ lru = page_lru(page);
+ nr_pages = hpage_nr_pages(page);
+
+ update_lru_size(lruvec, lru, page_zonenum(page), nr_pages);
+ list_add(&page->lru, &lruvec->lists[lru]);
+ nr_moved += nr_pages;
}
/*
We don't have to add a freeable page into lru and then remove from it. This change saves a couple of actions and makes the moving more clear. The SetPageLRU needs to be kept here for list intergrity. Otherwise: #0 mave_pages_to_lru #1 release_pages if (put_page_testzero()) if !put_page_testzero !PageLRU //skip lru_lock list_add(&page->lru,) list_add(&page->lru,) //corrupt Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/vmscan.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-)