Commonly, putback_lru_page is used with isolated_lru_page. The isolated_lru_page picks the page in middle of LRU and putback_lru_page insert the lru in head of LRU. It means it could make LRU churning so we have to be very careful. Let's clear description of putback_lru_page. Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Signed-off-by: Minchan Kim <minchan.kim@xxxxxxxxx> --- mm/migrate.c | 2 +- mm/vmscan.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 34132f8..819d233 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -68,7 +68,7 @@ int migrate_prep_local(void) } /* - * Add isolated pages on the list back to the LRU under page lock + * Add isolated pages on the list back to the LRU's head under page lock * to avoid leaking evictable pages back onto unevictable list. */ void putback_lru_pages(struct list_head *l) diff --git a/mm/vmscan.c b/mm/vmscan.c index e8d6190..5196f0c 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -551,10 +551,10 @@ int remove_mapping(struct address_space *mapping, struct page *page) } /** - * putback_lru_page - put previously isolated page onto appropriate LRU list + * putback_lru_page - put previously isolated page onto appropriate LRU list's head * @page: page to be put back to appropriate lru list * - * Add previously isolated @page to appropriate LRU list. + * Add previously isolated @page to appropriate LRU list's head * Page may still be unevictable for other reasons. * * lru_lock must not be held, interrupts must be enabled. -- 1.7.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>