diff options
| -rw-r--r-- | mm/mlock.c | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/mm/mlock.c b/mm/mlock.c index abdc612b042d..19a934dce5d6 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -303,8 +303,10 @@ static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone) if (PageLRU(page)) { lruvec = mem_cgroup_page_lruvec(page, zone); lru = page_lru(page); - - get_page(page); + /* + * We already have pin from follow_page_mask() + * so we can spare the get_page() here. + */ ClearPageLRU(page); del_page_from_lru_list(page, lruvec, lru); } else { @@ -336,25 +338,25 @@ skip_munlock: lock_page(page); if (!__putback_lru_fast_prepare(page, &pvec_putback, &pgrescued)) { - /* Slow path */ + /* + * Slow path. We don't want to lose the last + * pin before unlock_page() + */ + get_page(page); /* for putback_lru_page() */ __munlock_isolated_page(page); unlock_page(page); + put_page(page); /* from follow_page_mask() */ } } } - /* Phase 3: page putback for pages that qualified for the fast path */ + /* + * Phase 3: page putback for pages that qualified for the fast path + * This will also call put_page() to return pin from follow_page_mask() + */ if (pagevec_count(&pvec_putback)) __putback_lru_fast(&pvec_putback, pgrescued); - /* Phase 4: put_page to return pin from follow_page_mask() */ - for (i = 0; i < nr; i++) { - struct page *page = pvec->pages[i]; - - if (page) - put_page(page); - } - pagevec_reinit(pvec); } |