Messages in this thread Patch in this message | | | Date | Tue, 01 Jul 2008 17:26:51 +0900 | From | KOSAKI Motohiro <> | Subject | [resend][PATCH -mm] split_lru: fix pagevec_move_tail() doesn't treat unevictable page |
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Agghh! I am really stupid. I forgot CCed Andrew ;-)
So, I resend this.
-------------------------------------- even under writebacking, page can move to unevictable list. so shouldn't pagevec_move_tail() check unevictable?
if pagevec_move_tail() doesn't PageUnevictable(), below race can occur.
CPU1 CPU2 ================================================================== 1. rotate_reclaimable_page() 2. PageUnevictable(page) return 0 3. local_irq_save() 4. pagevec_move_tail() SetPageUnevictable() //mlock? move to unevictable list 5. spin_lock(&zone->lru_lock); 6. list_move_tail(); (move to inactive list)
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
--- mm/swap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Index: b/mm/swap.c =================================================================== --- a/mm/swap.c +++ b/mm/swap.c @@ -116,7 +116,7 @@ static void pagevec_move_tail(struct pag zone = pagezone; spin_lock(&zone->lru_lock); } - if (PageLRU(page) && !PageActive(page)) { + if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { int lru = page_is_file_cache(page); list_move_tail(&page->lru, &zone->lru[lru].list); pgmoved++;
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