diff options
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r-- | mm/vmscan.c | 213 |
1 files changed, 151 insertions, 62 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index ba8228e..613e89f 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -148,8 +148,8 @@ static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone, return &zone->reclaim_stat; } -static unsigned long zone_nr_pages(struct zone *zone, struct scan_control *sc, - enum lru_list lru) +static unsigned long zone_nr_lru_pages(struct zone *zone, + struct scan_control *sc, enum lru_list lru) { if (!scanning_global_lru(sc)) return mem_cgroup_zone_nr_pages(sc->mem_cgroup, zone, lru); @@ -286,7 +286,12 @@ static inline int page_mapping_inuse(struct page *page) static inline int is_page_cache_freeable(struct page *page) { - return page_count(page) - !!page_has_private(page) == 2; + /* + * A freeable page cache page is referenced only by the caller + * that isolated the page, the page cache radix tree and + * optional buffer heads at page->private. + */ + return page_count(page) - page_has_private(page) == 2; } static int may_write_to_queue(struct backing_dev_info *bdi) @@ -361,7 +366,6 @@ static pageout_t pageout(struct page *page, struct address_space *mapping, * block, for some throttling. This happens by accident, because * swap_backing_dev_info is bust: it doesn't reflect the * congestion state of the swapdevs. Easy to fix, if needed. - * See swapfile.c:page_queue_congested(). */ if (!is_page_cache_freeable(page)) return PAGE_KEEP; @@ -531,7 +535,7 @@ redo: * unevictable page on [in]active list. * We know how to handle that. */ - lru = active + page_is_file_cache(page); + lru = active + page_lru_base_type(page); lru_cache_add_lru(page, lru); } else { /* @@ -821,7 +825,7 @@ int __isolate_lru_page(struct page *page, int mode, int file) if (mode != ISOLATE_BOTH && (!PageActive(page) != !mode)) return ret; - if (mode != ISOLATE_BOTH && (!page_is_file_cache(page) != !file)) + if (mode != ISOLATE_BOTH && page_is_file_cache(page) != file) return ret; /* @@ -935,6 +939,16 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, /* Check that we have not crossed a zone boundary. */ if (unlikely(page_zone_id(cursor_page) != zone_id)) continue; + + /* + * If we don't have enough swap space, reclaiming of + * anon page which don't already have a swap slot is + * pointless. + */ + if (nr_swap_pages <= 0 && PageAnon(cursor_page) && + !PageSwapCache(cursor_page)) + continue; + if (__isolate_lru_page(cursor_page, mode, file) == 0) { list_move(&cursor_page->lru, dst); mem_cgroup_del_lru(cursor_page); @@ -961,7 +975,7 @@ static unsigned long isolate_pages_global(unsigned long nr, if (file) lru += LRU_FILE; return isolate_lru_pages(nr, &z->lru[lru].list, dst, scanned, order, - mode, !!file); + mode, file); } /* @@ -976,7 +990,7 @@ static unsigned long clear_active_flags(struct list_head *page_list, struct page *page; list_for_each_entry(page, page_list, lru) { - lru = page_is_file_cache(page); + lru = page_lru_base_type(page); if (PageActive(page)) { lru += LRU_ACTIVE; ClearPageActive(page); @@ -1034,6 +1048,31 @@ int isolate_lru_page(struct page *page) } /* + * Are there way too many processes in the direct reclaim path already? + */ +static int too_many_isolated(struct zone *zone, int file, + struct scan_control *sc) +{ + unsigned long inactive, isolated; + + if (current_is_kswapd()) + return 0; + + if (!scanning_global_lru(sc)) + return 0; + + if (file) { + inactive = zone_page_state(zone, NR_INACTIVE_FILE); + isolated = zone_page_state(zone, NR_ISOLATED_FILE); + } else { + inactive = zone_page_state(zone, NR_INACTIVE_ANON); + isolated = zone_page_state(zone, NR_ISOLATED_ANON); + } + + return isolated > inactive; +} + +/* * shrink_inactive_list() is a helper for shrink_zone(). It returns the number * of reclaimed pages */ @@ -1048,6 +1087,14 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); int lumpy_reclaim = 0; + while (unlikely(too_many_isolated(zone, file, sc))) { + congestion_wait(WRITE, HZ/10); + + /* We are about to die and free our memory. Return now. */ + if (fatal_signal_pending(current)) + return SWAP_CLUSTER_MAX; + } + /* * If we need a large contiguous chunk of memory, or have * trouble getting a small set of contiguous pages, we @@ -1072,10 +1119,26 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, unsigned long nr_active; unsigned int count[NR_LRU_LISTS] = { 0, }; int mode = lumpy_reclaim ? ISOLATE_BOTH : ISOLATE_INACTIVE; + unsigned long nr_anon; + unsigned long nr_file; nr_taken = sc->isolate_pages(sc->swap_cluster_max, &page_list, &nr_scan, sc->order, mode, zone, sc->mem_cgroup, 0, file); + + if (scanning_global_lru(sc)) { + zone->pages_scanned += nr_scan; + if (current_is_kswapd()) + __count_zone_vm_events(PGSCAN_KSWAPD, zone, + nr_scan); + else + __count_zone_vm_events(PGSCAN_DIRECT, zone, + nr_scan); + } + + if (nr_taken == 0) + goto done; + nr_active = clear_active_flags(&page_list, count); __count_vm_events(PGDEACTIVATE, nr_active); @@ -1088,8 +1151,10 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, __mod_zone_page_state(zone, NR_INACTIVE_ANON, -count[LRU_INACTIVE_ANON]); - if (scanning_global_lru(sc)) - zone->pages_scanned += nr_scan; + nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON]; + nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE]; + __mod_zone_page_state(zone, NR_ISOLATED_ANON, nr_anon); + __mod_zone_page_state(zone, NR_ISOLATED_FILE, nr_file); reclaim_stat->recent_scanned[0] += count[LRU_INACTIVE_ANON]; reclaim_stat->recent_scanned[0] += count[LRU_ACTIVE_ANON]; @@ -1123,18 +1188,12 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, } nr_reclaimed += nr_freed; + local_irq_disable(); - if (current_is_kswapd()) { - __count_zone_vm_events(PGSCAN_KSWAPD, zone, nr_scan); + if (current_is_kswapd()) __count_vm_events(KSWAPD_STEAL, nr_freed); - } else if (scanning_global_lru(sc)) - __count_zone_vm_events(PGSCAN_DIRECT, zone, nr_scan); - __count_zone_vm_events(PGSTEAL, zone, nr_freed); - if (nr_taken == 0) - goto done; - spin_lock(&zone->lru_lock); /* * Put back any unfreeable pages. @@ -1153,8 +1212,8 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, SetPageLRU(page); lru = page_lru(page); add_page_to_lru_list(zone, page, lru); - if (PageActive(page)) { - int file = !!page_is_file_cache(page); + if (is_active_lru(lru)) { + int file = is_file_lru(lru); reclaim_stat->recent_rotated[file]++; } if (!pagevec_add(&pvec, page)) { @@ -1163,10 +1222,13 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, spin_lock_irq(&zone->lru_lock); } } + __mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon); + __mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file); + } while (nr_scanned < max_scan); - spin_unlock(&zone->lru_lock); + done: - local_irq_enable(); + spin_unlock_irq(&zone->lru_lock); pagevec_release(&pvec); return nr_reclaimed; } @@ -1215,15 +1277,10 @@ static void move_active_pages_to_lru(struct zone *zone, while (!list_empty(list)) { page = lru_to_page(list); - prefetchw_prev_lru_page(page, list, flags); VM_BUG_ON(PageLRU(page)); SetPageLRU(page); - VM_BUG_ON(!PageActive(page)); - if (!is_active_lru(lru)) - ClearPageActive(page); /* we are de-activating */ - list_move(&page->lru, &zone->lru[lru].list); mem_cgroup_add_lru_list(page, lru); pgmoved++; @@ -1244,7 +1301,7 @@ static void move_active_pages_to_lru(struct zone *zone, static void shrink_active_list(unsigned long nr_pages, struct zone *zone, struct scan_control *sc, int priority, int file) { - unsigned long pgmoved; + unsigned long nr_taken; unsigned long pgscanned; unsigned long vm_flags; LIST_HEAD(l_hold); /* The pages which were snipped off */ @@ -1252,10 +1309,11 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, LIST_HEAD(l_inactive); struct page *page; struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); + unsigned long nr_rotated = 0; lru_add_drain(); spin_lock_irq(&zone->lru_lock); - pgmoved = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order, + nr_taken = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order, ISOLATE_ACTIVE, zone, sc->mem_cgroup, 1, file); /* @@ -1265,16 +1323,16 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, if (scanning_global_lru(sc)) { zone->pages_scanned += pgscanned; } - reclaim_stat->recent_scanned[!!file] += pgmoved; + reclaim_stat->recent_scanned[file] += nr_taken; __count_zone_vm_events(PGREFILL, zone, pgscanned); if (file) - __mod_zone_page_state(zone, NR_ACTIVE_FILE, -pgmoved); + __mod_zone_page_state(zone, NR_ACTIVE_FILE, -nr_taken); else - __mod_zone_page_state(zone, NR_ACTIVE_ANON, -pgmoved); + __mod_zone_page_state(zone, NR_ACTIVE_ANON, -nr_taken); + __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, nr_taken); spin_unlock_irq(&zone->lru_lock); - pgmoved = 0; /* count referenced (mapping) mapped pages */ while (!list_empty(&l_hold)) { cond_resched(); page = lru_to_page(&l_hold); @@ -1288,7 +1346,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, /* page_referenced clears PageReferenced */ if (page_mapping_inuse(page) && page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) { - pgmoved++; + nr_rotated++; /* * Identify referenced, file-backed active pages and * give them one more trip around the active list. So @@ -1304,6 +1362,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, } } + ClearPageActive(page); /* we are de-activating */ list_add(&page->lru, &l_inactive); } @@ -1317,13 +1376,13 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, * helps balance scan pressure between file and anonymous pages in * get_scan_ratio. */ - reclaim_stat->recent_rotated[!!file] += pgmoved; + reclaim_stat->recent_rotated[file] += nr_rotated; move_active_pages_to_lru(zone, &l_active, LRU_ACTIVE + file * LRU_FILE); move_active_pages_to_lru(zone, &l_inactive, LRU_BASE + file * LRU_FILE); - + __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, -nr_taken); spin_unlock_irq(&zone->lru_lock); } @@ -1429,10 +1488,10 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc, unsigned long ap, fp; struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); - anon = zone_nr_pages(zone, sc, LRU_ACTIVE_ANON) + - zone_nr_pages(zone, sc, LRU_INACTIVE_ANON); - file = zone_nr_pages(zone, sc, LRU_ACTIVE_FILE) + - zone_nr_pages(zone, sc, LRU_INACTIVE_FILE); + anon = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) + + zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON); + file = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) + + zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE); if (scanning_global_lru(sc)) { free = zone_page_state(zone, NR_FREE_PAGES); @@ -1526,6 +1585,7 @@ static void shrink_zone(int priority, struct zone *zone, enum lru_list l; unsigned long nr_reclaimed = sc->nr_reclaimed; unsigned long swap_cluster_max = sc->swap_cluster_max; + struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); int noswap = 0; /* If we have no swap space, do not bother scanning anon pages. */ @@ -1540,17 +1600,14 @@ static void shrink_zone(int priority, struct zone *zone, int file = is_file_lru(l); unsigned long scan; - scan = zone_nr_pages(zone, sc, l); + scan = zone_nr_lru_pages(zone, sc, l); if (priority || noswap) { scan >>= priority; scan = (scan * percent[file]) / 100; } - if (scanning_global_lru(sc)) - nr[l] = nr_scan_try_batch(scan, - &zone->lru[l].nr_saved_scan, - swap_cluster_max); - else - nr[l] = scan; + nr[l] = nr_scan_try_batch(scan, + &reclaim_stat->nr_saved_scan[l], + swap_cluster_max); } while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] || @@ -1685,7 +1742,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) continue; - lru_pages += zone_lru_pages(zone); + lru_pages += zone_reclaimable_pages(zone); } } @@ -1902,7 +1959,7 @@ loop_again: for (i = 0; i <= end_zone; i++) { struct zone *zone = pgdat->node_zones + i; - lru_pages += zone_lru_pages(zone); + lru_pages += zone_reclaimable_pages(zone); } /* @@ -1946,7 +2003,7 @@ loop_again: if (zone_is_all_unreclaimable(zone)) continue; if (nr_slab == 0 && zone->pages_scanned >= - (zone_lru_pages(zone) * 6)) + (zone_reclaimable_pages(zone) * 6)) zone_set_flag(zone, ZONE_ALL_UNRECLAIMABLE); /* @@ -2113,12 +2170,39 @@ void wakeup_kswapd(struct zone *zone, int order) wake_up_interruptible(&pgdat->kswapd_wait); } -unsigned long global_lru_pages(void) +/* + * The reclaimable count would be mostly accurate. + * The less reclaimable pages may be + * - mlocked pages, which will be moved to unevictable list when encountered + * - mapped pages, which may require several travels to be reclaimed + * - dirty pages, which is not "instantly" reclaimable + */ +unsigned long global_reclaimable_pages(void) +{ + int nr; + + nr = global_page_state(NR_ACTIVE_FILE) + + global_page_state(NR_INACTIVE_FILE); + + if (nr_swap_pages > 0) + nr += global_page_state(NR_ACTIVE_ANON) + + global_page_state(NR_INACTIVE_ANON); + + return nr; +} + +unsigned long zone_reclaimable_pages(struct zone *zone) { - return global_page_state(NR_ACTIVE_ANON) - + global_page_state(NR_ACTIVE_FILE) - + global_page_state(NR_INACTIVE_ANON) - + global_page_state(NR_INACTIVE_FILE); + int nr; + + nr = zone_page_state(zone, NR_ACTIVE_FILE) + + zone_page_state(zone, NR_INACTIVE_FILE); + + if (nr_swap_pages > 0) + nr += zone_page_state(zone, NR_ACTIVE_ANON) + + zone_page_state(zone, NR_INACTIVE_ANON); + + return nr; } #ifdef CONFIG_HIBERNATION @@ -2133,6 +2217,7 @@ static void shrink_all_zones(unsigned long nr_pages, int prio, { struct zone *zone; unsigned long nr_reclaimed = 0; + struct zone_reclaim_stat *reclaim_stat; for_each_populated_zone(zone) { enum lru_list l; @@ -2149,11 +2234,14 @@ static void shrink_all_zones(unsigned long nr_pages, int prio, l == LRU_ACTIVE_FILE)) continue; - zone->lru[l].nr_saved_scan += (lru_pages >> prio) + 1; - if (zone->lru[l].nr_saved_scan >= nr_pages || pass > 3) { + reclaim_stat = get_reclaim_stat(zone, sc); + reclaim_stat->nr_saved_scan[l] += + (lru_pages >> prio) + 1; + if (reclaim_stat->nr_saved_scan[l] + >= nr_pages || pass > 3) { unsigned long nr_to_scan; - zone->lru[l].nr_saved_scan = 0; + reclaim_stat->nr_saved_scan[l] = 0; nr_to_scan = min(nr_pages, lru_pages); nr_reclaimed += shrink_list(l, nr_to_scan, zone, sc, prio); @@ -2190,7 +2278,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages) current->reclaim_state = &reclaim_state; - lru_pages = global_lru_pages(); + lru_pages = global_reclaimable_pages(); nr_slab = global_page_state(NR_SLAB_RECLAIMABLE); /* If slab caches are huge, it's better to hit them first */ while (nr_slab >= lru_pages) { @@ -2232,7 +2320,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages) reclaim_state.reclaimed_slab = 0; shrink_slab(sc.nr_scanned, sc.gfp_mask, - global_lru_pages()); + global_reclaimable_pages()); sc.nr_reclaimed += reclaim_state.reclaimed_slab; if (sc.nr_reclaimed >= nr_pages) goto out; @@ -2249,7 +2337,8 @@ unsigned long shrink_all_memory(unsigned long nr_pages) if (!sc.nr_reclaimed) { do { reclaim_state.reclaimed_slab = 0; - shrink_slab(nr_pages, sc.gfp_mask, global_lru_pages()); + shrink_slab(nr_pages, sc.gfp_mask, + global_reclaimable_pages()); sc.nr_reclaimed += reclaim_state.reclaimed_slab; } while (sc.nr_reclaimed < nr_pages && reclaim_state.reclaimed_slab > 0); @@ -2569,7 +2658,7 @@ static void check_move_unevictable_page(struct page *page, struct zone *zone) retry: ClearPageUnevictable(page); if (page_evictable(page, NULL)) { - enum lru_list l = LRU_INACTIVE_ANON + page_is_file_cache(page); + enum lru_list l = page_lru_base_type(page); __dec_zone_state(zone, NR_UNEVICTABLE); list_move(&page->lru, &zone->lru[l].list); |