Messages in this thread Patch in this message | | | Date | Fri, 6 Jul 2007 18:24:20 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | [PATCH] memory unplug v7 [2/6] - isolate_lru_page fix |
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release_pages() in mm/swap.c changes page_count() to be 0 without removing PageLRU flag...
This means isolate_lru_page() can see a page, PageLRU() && page_count(page)==0.. This is BUG. (get_page() will be called against count=0 page.)
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
--- mm/migrate.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
Index: linux-2.6.22-rc6-mm1/mm/migrate.c =================================================================== --- linux-2.6.22-rc6-mm1.orig/mm/migrate.c +++ linux-2.6.22-rc6-mm1/mm/migrate.c @@ -49,9 +49,8 @@ int isolate_lru_page(struct page *page, struct zone *zone = page_zone(page); spin_lock_irq(&zone->lru_lock); - if (PageLRU(page)) { + if (PageLRU(page) && get_page_unless_zero(page)) { ret = 0; - get_page(page); ClearPageLRU(page); if (PageActive(page)) del_page_from_active_list(zone, page); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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