diff options
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 90 |
1 files changed, 17 insertions, 73 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 444749669187..cd5dc3faaa57 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -769,64 +769,7 @@ int remove_mapping(struct address_space *mapping, struct page *page) */ void putback_lru_page(struct page *page) { - bool is_unevictable; - int was_unevictable = PageUnevictable(page); - - VM_BUG_ON_PAGE(PageLRU(page), page); - -redo: - ClearPageUnevictable(page); - - if (page_evictable(page)) { - /* - * For evictable pages, we can use the cache. - * In event of a race, worst case is we end up with an - * unevictable page on [in]active list. - * We know how to handle that. - */ - is_unevictable = false; - lru_cache_add(page); - } else { - /* - * Put unevictable pages directly on zone's unevictable - * list. - */ - is_unevictable = true; - add_page_to_unevictable_list(page); - /* - * When racing with an mlock or AS_UNEVICTABLE clearing - * (page is unlocked) make sure that if the other thread - * does not observe our setting of PG_lru and fails - * isolation/check_move_unevictable_pages, - * we see PG_mlocked/AS_UNEVICTABLE cleared below and move - * the page back to the evictable list. - * - * The other side is TestClearPageMlocked() or shmem_lock(). - */ - smp_mb(); - } - - /* - * page's status can change while we move it among lru. If an evictable - * page is on unevictable list, it never be freed. To avoid that, - * check after we added it to the list, again. - */ - if (is_unevictable && page_evictable(page)) { - if (!isolate_lru_page(page)) { - put_page(page); - goto redo; - } - /* This means someone else dropped this page from LRU - * So, it will be freed or putback to LRU again. There is - * nothing to do here. - */ - } - - if (was_unevictable && !is_unevictable) - count_vm_event(UNEVICTABLE_PGRESCUED); - else if (!was_unevictable && is_unevictable) - count_vm_event(UNEVICTABLE_PGCULLED); - + lru_cache_add(page); put_page(page); /* drop ref from isolate */ } @@ -1837,6 +1780,20 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, set_bit(PGDAT_WRITEBACK, &pgdat->flags); /* + * If dirty pages are scanned that are not queued for IO, it + * implies that flushers are not doing their job. This can + * happen when memory pressure pushes dirty pages to the end of + * the LRU before the dirty limits are breached and the dirty + * data has expired. It can also happen when the proportion of + * dirty pages grows not through writes but through memory + * pressure reclaiming all the clean cache. And in some cases, + * the flushers simply cannot keep up with the allocation + * rate. Nudge the flusher threads in case they are asleep. + */ + if (stat.nr_unqueued_dirty == nr_taken) + wakeup_flusher_threads(WB_REASON_VMSCAN); + + /* * Legacy memcg will stall in page writeback so avoid forcibly * stalling here. */ @@ -1848,22 +1805,9 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, if (stat.nr_dirty && stat.nr_dirty == stat.nr_congested) set_bit(PGDAT_CONGESTED, &pgdat->flags); - /* - * If dirty pages are scanned that are not queued for IO, it - * implies that flushers are not doing their job. This can - * happen when memory pressure pushes dirty pages to the end of - * the LRU before the dirty limits are breached and the dirty - * data has expired. It can also happen when the proportion of - * dirty pages grows not through writes but through memory - * pressure reclaiming all the clean cache. And in some cases, - * the flushers simply cannot keep up with the allocation - * rate. Nudge the flusher threads in case they are asleep, but - * also allow kswapd to start writing pages during reclaim. - */ - if (stat.nr_unqueued_dirty == nr_taken) { - wakeup_flusher_threads(WB_REASON_VMSCAN); + /* Allow kswapd to start writing pages during reclaim. */ + if (stat.nr_unqueued_dirty == nr_taken) set_bit(PGDAT_DIRTY, &pgdat->flags); - } /* * If kswapd scans pages marked marked for immediate |