1 files changed, 149 insertions, 172 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 777af57fd8c8..885207a6b6b7 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -55,6 +55,11 @@ struct scan_control {
         /* Number of pages freed so far during a call to shrink_zones() */
         unsigned long nr_reclaimed;
 
+        /* How many pages shrink_list() should reclaim */
+        unsigned long nr_to_reclaim;
+
+        unsigned long hibernation_mode;
+
         /* This context's GFP mask */
         gfp_t gfp_mask;
 
@@ -66,12 +71,6 @@ struct scan_control {
         /* Can pages be swapped as part of reclaim? */
         int may_swap;
 
-        /* This context's SWAP_CLUSTER_MAX. If freeing memory for
-         * suspend, we effectively ignore SWAP_CLUSTER_MAX.
-         * In this context, it doesn't matter that we scan the
-         * whole list at once. */
-        int swap_cluster_max;
-
         int swappiness;
 
         int all_unreclaimable;
@@ -358,7 +357,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
          * stalls if we need to run get_block().  We could test
          * PagePrivate for that.
          *
-         * If this process is currently in generic_file_write() against
+         * If this process is currently in __generic_file_aio_write() against
          * this page's queue, we can perform writeback even if that
          * will block.
          *
@@ -1132,7 +1131,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                 unsigned long nr_anon;
                 unsigned long nr_file;
 
-                nr_taken = sc->isolate_pages(sc->swap_cluster_max,
+                nr_taken = sc->isolate_pages(SWAP_CLUSTER_MAX,
                              &page_list, &nr_scan, sc->order, mode,
                                 zone, sc->mem_cgroup, 0, file);
 
@@ -1166,10 +1165,8 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                 __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];
-                reclaim_stat->recent_scanned[1] += count[LRU_INACTIVE_FILE];
-                reclaim_stat->recent_scanned[1] += count[LRU_ACTIVE_FILE];
+                reclaim_stat->recent_scanned[0] += nr_anon;
+                reclaim_stat->recent_scanned[1] += nr_file;
 
                 spin_unlock_irq(&zone->lru_lock);
 
@@ -1464,20 +1461,26 @@ static int inactive_file_is_low(struct zone *zone, struct scan_control *sc)
         return low;
 }
 
+static int inactive_list_is_low(struct zone *zone, struct scan_control *sc,
+                                int file)
+{
+        if (file)
+                return inactive_file_is_low(zone, sc);
+        else
+                return inactive_anon_is_low(zone, sc);
+}
+
 static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
         struct zone *zone, struct scan_control *sc, int priority)
 {
         int file = is_file_lru(lru);
 
-        if (lru == LRU_ACTIVE_FILE && inactive_file_is_low(zone, sc)) {
-                shrink_active_list(nr_to_scan, zone, sc, priority, file);
+        if (is_active_lru(lru)) {
+                if (inactive_list_is_low(zone, sc, file))
+                    shrink_active_list(nr_to_scan, zone, sc, priority, file);
                 return 0;
         }
 
-        if (lru == LRU_ACTIVE_ANON && inactive_anon_is_low(zone, sc)) {
-                shrink_active_list(nr_to_scan, zone, sc, priority, file);
-                return 0;
-        }
         return shrink_inactive_list(nr_to_scan, zone, sc, priority, file);
 }
 
@@ -1567,15 +1570,14 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
  * until we collected @swap_cluster_max pages to scan.
  */
 static unsigned long nr_scan_try_batch(unsigned long nr_to_scan,
-                                       unsigned long *nr_saved_scan,
-                                       unsigned long swap_cluster_max)
+                                       unsigned long *nr_saved_scan)
 {
         unsigned long nr;
 
         *nr_saved_scan += nr_to_scan;
         nr = *nr_saved_scan;
 
-        if (nr >= swap_cluster_max)
+        if (nr >= SWAP_CLUSTER_MAX)
                 *nr_saved_scan = 0;
         else
                 nr = 0;
@@ -1594,7 +1596,7 @@ static void shrink_zone(int priority, struct zone *zone,
         unsigned long percent[2];       /* anon @ 0; file @ 1 */
         enum lru_list l;
         unsigned long nr_reclaimed = sc->nr_reclaimed;
-        unsigned long swap_cluster_max = sc->swap_cluster_max;
+        unsigned long nr_to_reclaim = sc->nr_to_reclaim;
         struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
         int noswap = 0;
 
@@ -1616,15 +1618,15 @@ static void shrink_zone(int priority, struct zone *zone,
                         scan = (scan * percent[file]) / 100;
                 }
                 nr[l] = nr_scan_try_batch(scan,
-                                          &reclaim_stat->nr_saved_scan[l],
-                                          swap_cluster_max);
+                                          &reclaim_stat->nr_saved_scan[l]);
         }
 
         while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
                                         nr[LRU_INACTIVE_FILE]) {
                 for_each_evictable_lru(l) {
                         if (nr[l]) {
-                                nr_to_scan = min(nr[l], swap_cluster_max);
+                                nr_to_scan = min_t(unsigned long,
+                                                   nr[l], SWAP_CLUSTER_MAX);
                                 nr[l] -= nr_to_scan;
 
                                 nr_reclaimed += shrink_list(l, nr_to_scan,
@@ -1639,8 +1641,7 @@ static void shrink_zone(int priority, struct zone *zone,
                  * with multiple processes reclaiming pages, the total
                  * freeing target can get unreasonably large.
                  */
-                if (nr_reclaimed > swap_cluster_max &&
-                        priority < DEF_PRIORITY && !current_is_kswapd())
+                if (nr_reclaimed >= nr_to_reclaim && priority < DEF_PRIORITY)
                         break;
         }
 
@@ -1738,6 +1739,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
         struct zoneref *z;
         struct zone *zone;
         enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask);
+        unsigned long writeback_threshold;
 
         delayacct_freepages_start();
 
@@ -1773,7 +1775,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                         }
                 }
                 total_scanned += sc->nr_scanned;
-                if (sc->nr_reclaimed >= sc->swap_cluster_max) {
+                if (sc->nr_reclaimed >= sc->nr_to_reclaim) {
                         ret = sc->nr_reclaimed;
                         goto out;
                 }
@@ -1785,14 +1787,15 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                  * that's undesirable in laptop mode, where we *want* lumpy
                  * writeout.  So in laptop mode, write out the whole world.
                  */
-                if (total_scanned > sc->swap_cluster_max +
-                                        sc->swap_cluster_max / 2) {
+                writeback_threshold = sc->nr_to_reclaim + sc->nr_to_reclaim / 2;
+                if (total_scanned > writeback_threshold) {
                         wakeup_flusher_threads(laptop_mode ? 0 : total_scanned);
                         sc->may_writepage = 1;
                 }
 
                 /* Take a nap, wait for some writeback to complete */
-                if (sc->nr_scanned && priority < DEF_PRIORITY - 2)
+                if (!sc->hibernation_mode && sc->nr_scanned &&
+                    priority < DEF_PRIORITY - 2)
                         congestion_wait(BLK_RW_ASYNC, HZ/10);
         }
         /* top priority shrink_zones still had more to do? don't OOM, then */
@@ -1831,7 +1834,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
         struct scan_control sc = {
                 .gfp_mask = gfp_mask,
                 .may_writepage = !laptop_mode,
-                .swap_cluster_max = SWAP_CLUSTER_MAX,
+                .nr_to_reclaim = SWAP_CLUSTER_MAX,
                 .may_unmap = 1,
                 .may_swap = 1,
                 .swappiness = vm_swappiness,
@@ -1855,7 +1858,6 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
                 .may_writepage = !laptop_mode,
                 .may_unmap = 1,
                 .may_swap = !noswap,
-                .swap_cluster_max = SWAP_CLUSTER_MAX,
                 .swappiness = swappiness,
                 .order = 0,
                 .mem_cgroup = mem,
@@ -1889,7 +1891,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
                 .may_writepage = !laptop_mode,
                 .may_unmap = 1,
                 .may_swap = !noswap,
-                .swap_cluster_max = SWAP_CLUSTER_MAX,
+                .nr_to_reclaim = SWAP_CLUSTER_MAX,
                 .swappiness = swappiness,
                 .order = 0,
                 .mem_cgroup = mem_cont,
@@ -1904,6 +1906,30 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 }
 #endif
 
+/* is kswapd sleeping prematurely? */
+static int sleeping_prematurely(pg_data_t *pgdat, int order, long remaining)
+{
+        int i;
+
+        /* If a direct reclaimer woke kswapd within HZ/10, it's premature */
+        if (remaining)
+                return 1;
+
+        /* If after HZ/10, a zone is below the high mark, it's premature */
+        for (i = 0; i < pgdat->nr_zones; i++) {
+                struct zone *zone = pgdat->node_zones + i;
+
+                if (!populated_zone(zone))
+                        continue;
+
+                if (!zone_watermark_ok(zone, order, high_wmark_pages(zone),
+                                                                0, 0))
+                        return 1;
+        }
+
+        return 0;
+}
+
 /*
  * For kswapd, balance_pgdat() will work across all this node's zones until
  * they are all at high_wmark_pages(zone).
@@ -1936,7 +1962,11 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order)
                 .gfp_mask = GFP_KERNEL,
                 .may_unmap = 1,
                 .may_swap = 1,
-                .swap_cluster_max = SWAP_CLUSTER_MAX,
+                /*
+                 * kswapd doesn't want to be bailed out while reclaim. because
+                 * we want to put equal scanning pressure on each zone.
+                 */
+                .nr_to_reclaim = ULONG_MAX,
                 .swappiness = vm_swappiness,
                 .order = order,
                 .mem_cgroup = NULL,
@@ -1961,6 +1991,7 @@ loop_again:
         for (priority = DEF_PRIORITY; priority >= 0; priority--) {
                 int end_zone = 0;       /* Inclusive.  0 = ZONE_DMA */
                 unsigned long lru_pages = 0;
+                int has_under_min_watermark_zone = 0;
 
                 /* The swap token gets in the way of swapout... */
                 if (!priority)
@@ -2067,6 +2098,15 @@ loop_again:
                         if (total_scanned > SWAP_CLUSTER_MAX * 2 &&
                             total_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2)
                                 sc.may_writepage = 1;
+
+                        /*
+                         * We are still under min water mark. it mean we have
+                         * GFP_ATOMIC allocation failure risk. Hurry up!
+                         */
+                        if (!zone_watermark_ok(zone, order, min_wmark_pages(zone),
+                                              end_zone, 0))
+                                has_under_min_watermark_zone = 1;
+
                 }
                 if (all_zones_ok)
                         break;          /* kswapd: all done */
@@ -2074,8 +2114,12 @@ loop_again:
                  * OK, kswapd is getting into trouble.  Take a nap, then take
                  * another pass across the zones.
                  */
-                if (total_scanned && priority < DEF_PRIORITY - 2)
-                        congestion_wait(BLK_RW_ASYNC, HZ/10);
+                if (total_scanned && (priority < DEF_PRIORITY - 2)) {
+                        if (has_under_min_watermark_zone)
+                                count_vm_event(KSWAPD_SKIP_CONGESTION_WAIT);
+                        else
+                                congestion_wait(BLK_RW_ASYNC, HZ/10);
+                }
 
                 /*
                  * We do this so kswapd doesn't build up large priorities for
@@ -2173,6 +2217,7 @@ static int kswapd(void *p)
         order = 0;
         for ( ; ; ) {
                 unsigned long new_order;
+                int ret;
 
                 prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
                 new_order = pgdat->kswapd_max_order;
@@ -2184,19 +2229,45 @@ static int kswapd(void *p)
                          */
                         order = new_order;
                 } else {
-                        if (!freezing(current))
-                                schedule();
+                        if (!freezing(current) && !kthread_should_stop()) {
+                                long remaining = 0;
+
+                                /* Try to sleep for a short interval */
+                                if (!sleeping_prematurely(pgdat, order, remaining)) {
+                                        remaining = schedule_timeout(HZ/10);
+                                        finish_wait(&pgdat->kswapd_wait, &wait);
+                                        prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
+                                }
+
+                                /*
+                                 * After a short sleep, check if it was a
+                                 * premature sleep. If not, then go fully
+                                 * to sleep until explicitly woken up
+                                 */
+                                if (!sleeping_prematurely(pgdat, order, remaining))
+                                        schedule();
+                                else {
+                                        if (remaining)
+                                                count_vm_event(KSWAPD_LOW_WMARK_HIT_QUICKLY);
+                                        else
+                                                count_vm_event(KSWAPD_HIGH_WMARK_HIT_QUICKLY);
+                                }
+                        }
 
                         order = pgdat->kswapd_max_order;
                 }
                 finish_wait(&pgdat->kswapd_wait, &wait);
 
-                if (!try_to_freeze()) {
-                        /* We can speed up thawing tasks if we don't call
-                         * balance_pgdat after returning from the refrigerator
-                         */
+                ret = try_to_freeze();
+                if (kthread_should_stop())
+                        break;
+
+                /*
+                 * We can speed up thawing tasks if we don't call balance_pgdat
+                 * after returning from the refrigerator
+                 */
+                if (!ret)
                         balance_pgdat(pgdat, order);
-                }
         }
         return 0;
 }
@@ -2260,148 +2331,43 @@ unsigned long zone_reclaimable_pages(struct zone *zone)
 
 #ifdef CONFIG_HIBERNATION
 /*
- * Helper function for shrink_all_memory().  Tries to reclaim 'nr_pages' pages
- * from LRU lists system-wide, for given pass and priority.
- *
- * For pass > 3 we also try to shrink the LRU lists that contain a few pages
- */
-static void shrink_all_zones(unsigned long nr_pages, int prio,
-                                      int pass, struct scan_control *sc)
-{
-        struct zone *zone;
-        unsigned long nr_reclaimed = 0;
-        struct zone_reclaim_stat *reclaim_stat;
-
-        for_each_populated_zone(zone) {
-                enum lru_list l;
-
-                if (zone_is_all_unreclaimable(zone) && prio != DEF_PRIORITY)
-                        continue;
-
-                for_each_evictable_lru(l) {
-                        enum zone_stat_item ls = NR_LRU_BASE + l;
-                        unsigned long lru_pages = zone_page_state(zone, ls);
-
-                        /* For pass = 0, we don't shrink the active list */
-                        if (pass == 0 && (l == LRU_ACTIVE_ANON ||
-                                                l == LRU_ACTIVE_FILE))
-                                continue;
-
-                        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;
-
-                                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);
-                                if (nr_reclaimed >= nr_pages) {
-                                        sc->nr_reclaimed += nr_reclaimed;
-                                        return;
-                                }
-                        }
-                }
-        }
-        sc->nr_reclaimed += nr_reclaimed;
-}
-
-/*
- * Try to free `nr_pages' of memory, system-wide, and return the number of
+ * Try to free `nr_to_reclaim' of memory, system-wide, and return the number of
  * freed pages.
  *
  * Rather than trying to age LRUs the aim is to preserve the overall
  * LRU order by reclaiming preferentially
  * inactive > active > active referenced > active mapped
  */
-unsigned long shrink_all_memory(unsigned long nr_pages)
+unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
 {
-        unsigned long lru_pages, nr_slab;
-        int pass;
         struct reclaim_state reclaim_state;
         struct scan_control sc = {
-                .gfp_mask = GFP_KERNEL,
-                .may_unmap = 0,
+                .gfp_mask = GFP_HIGHUSER_MOVABLE,
+                .may_swap = 1,
+                .may_unmap = 1,
                 .may_writepage = 1,
+                .nr_to_reclaim = nr_to_reclaim,
+                .hibernation_mode = 1,
+                .swappiness = vm_swappiness,
+                .order = 0,
                 .isolate_pages = isolate_pages_global,
-                .nr_reclaimed = 0,
         };
+        struct zonelist * zonelist = node_zonelist(numa_node_id(), sc.gfp_mask);
+        struct task_struct *p = current;
+        unsigned long nr_reclaimed;
 
-        current->reclaim_state = &reclaim_state;
-
-        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) {
-                reclaim_state.reclaimed_slab = 0;
-                shrink_slab(nr_pages, sc.gfp_mask, lru_pages);
-                if (!reclaim_state.reclaimed_slab)
-                        break;
-
-                sc.nr_reclaimed += reclaim_state.reclaimed_slab;
-                if (sc.nr_reclaimed >= nr_pages)
-                        goto out;
-
-                nr_slab -= reclaim_state.reclaimed_slab;
-        }
-
-        /*
-         * We try to shrink LRUs in 5 passes:
-         * 0 = Reclaim from inactive_list only
-         * 1 = Reclaim from active list but don't reclaim mapped
-         * 2 = 2nd pass of type 1
-         * 3 = Reclaim mapped (normal reclaim)
-         * 4 = 2nd pass of type 3
-         */
-        for (pass = 0; pass < 5; pass++) {
-                int prio;
-
-                /* Force reclaiming mapped pages in the passes #3 and #4 */
-                if (pass > 2)
-                        sc.may_unmap = 1;
-
-                for (prio = DEF_PRIORITY; prio >= 0; prio--) {
-                        unsigned long nr_to_scan = nr_pages - sc.nr_reclaimed;
-
-                        sc.nr_scanned = 0;
-                        sc.swap_cluster_max = nr_to_scan;
-                        shrink_all_zones(nr_to_scan, prio, pass, &sc);
-                        if (sc.nr_reclaimed >= nr_pages)
-                                goto out;
-
-                        reclaim_state.reclaimed_slab = 0;
-                        shrink_slab(sc.nr_scanned, sc.gfp_mask,
-                                    global_reclaimable_pages());
-                        sc.nr_reclaimed += reclaim_state.reclaimed_slab;
-                        if (sc.nr_reclaimed >= nr_pages)
-                                goto out;
-
-                        if (sc.nr_scanned && prio < DEF_PRIORITY - 2)
-                                congestion_wait(BLK_RW_ASYNC, HZ / 10);
-                }
-        }
-
-        /*
-         * If sc.nr_reclaimed = 0, we could not shrink LRUs, but there may be
-         * something in slab caches
-         */
-        if (!sc.nr_reclaimed) {
-                do {
-                        reclaim_state.reclaimed_slab = 0;
-                        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);
-        }
+        p->flags |= PF_MEMALLOC;
+        lockdep_set_current_reclaim_state(sc.gfp_mask);
+        reclaim_state.reclaimed_slab = 0;
+        p->reclaim_state = &reclaim_state;
 
+        nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
 
-out:
-        current->reclaim_state = NULL;
+        p->reclaim_state = NULL;
+        lockdep_clear_current_reclaim_state();
+        p->flags &= ~PF_MEMALLOC;
 
-        return sc.nr_reclaimed;
+        return nr_reclaimed;
 }
 #endif /* CONFIG_HIBERNATION */
 
@@ -2451,6 +2417,17 @@ int kswapd_run(int nid)
         return ret;
 }
 
+/*
+ * Called by memory hotplug when all memory in a node is offlined.
+ */
+void kswapd_stop(int nid)
+{
+        struct task_struct *kswapd = NODE_DATA(nid)->kswapd;
+
+        if (kswapd)
+                kthread_stop(kswapd);
+}
+
 static int __init kswapd_init(void)
 {
         int nid;
@@ -2553,8 +2530,8 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
                 .may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE),
                 .may_unmap = !!(zone_reclaim_mode & RECLAIM_SWAP),
                 .may_swap = 1,
-                .swap_cluster_max = max_t(unsigned long, nr_pages,
-                                        SWAP_CLUSTER_MAX),
+                .nr_to_reclaim = max_t(unsigned long, nr_pages,
+                                       SWAP_CLUSTER_MAX),
                 .gfp_mask = gfp_mask,
                 .swappiness = vm_swappiness,
                 .order = order,