After each migration attempt, putback_lru_page() is used to drop the last reference to the page. This is fine but it prevents the batching of TLB flushes because the flush must happen before a free. This patch drops all the migrated pages at once in preparation for batching the TLB flush.
Signed-off-by: Mel Gorman <[email protected]> --- mm/migrate.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 85e042686031..82c98c5aa6ed 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -906,7 +906,7 @@ out: */ static int unmap_and_move(new_page_t get_new_page, free_page_t put_new_page, unsigned long private, struct page *page, int force, - enum migrate_mode mode) + enum migrate_mode mode, struct list_head *putback_list) { int rc = 0; int *result = NULL; @@ -937,7 +937,7 @@ out: list_del(&page->lru); dec_zone_page_state(page, NR_ISOLATED_ANON + page_is_file_cache(page)); - putback_lru_page(page); + list_add(&page->lru, putback_list); } /* @@ -1086,6 +1086,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, free_page_t put_new_page, unsigned long private, enum migrate_mode mode, int reason) { + LIST_HEAD(putback_list); int retry = 1; int nr_failed = 0; int nr_succeeded = 0; @@ -1110,7 +1111,8 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, pass > 2, mode); else rc = unmap_and_move(get_new_page, put_new_page, - private, page, pass > 2, mode); + private, page, pass > 2, mode, + &putback_list); switch(rc) { case -ENOMEM: @@ -1135,6 +1137,12 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, } rc = nr_failed + retry; out: + while (!list_empty(&putback_list)) { + page = list_entry(putback_list.prev, struct page, lru); + list_del(&page->lru); + putback_lru_page(page); + } + if (nr_succeeded) count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded); if (nr_failed) -- 2.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
