[media] media: Fix media device minor registration
[pandora-kernel.git] / mm / vmscan.c
index 7e01161..faa0a08 100644 (file)
@@ -173,7 +173,7 @@ 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);
+               return mem_cgroup_zone_nr_lru_pages(sc->mem_cgroup, zone, lru);
 
        return zone_page_state(zone, NR_LRU_BASE + lru);
 }
@@ -1717,26 +1717,6 @@ static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
        return shrink_inactive_list(nr_to_scan, zone, sc, priority, file);
 }
 
-/*
- * Smallish @nr_to_scan's are deposited in @nr_saved_scan,
- * 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 nr;
-
-       *nr_saved_scan += nr_to_scan;
-       nr = *nr_saved_scan;
-
-       if (nr >= SWAP_CLUSTER_MAX)
-               *nr_saved_scan = 0;
-       else
-               nr = 0;
-
-       return nr;
-}
-
 /*
  * Determine how aggressively the anon and file LRU lists should be
  * scanned.  The relative value of each set of LRU lists is determined
@@ -1755,6 +1735,22 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
        u64 fraction[2], denominator;
        enum lru_list l;
        int noswap = 0;
+       int force_scan = 0;
+
+
+       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 (((anon + file) >> priority) < SWAP_CLUSTER_MAX) {
+               /* kswapd does zone balancing and need to scan this zone */
+               if (scanning_global_lru(sc) && current_is_kswapd())
+                       force_scan = 1;
+               /* memcg may have small limit and need to avoid priority drop */
+               if (!scanning_global_lru(sc))
+                       force_scan = 1;
+       }
 
        /* If we have no swap space, do not bother scanning anon pages. */
        if (!sc->may_swap || (nr_swap_pages <= 0)) {
@@ -1765,11 +1761,6 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
                goto out;
        }
 
-       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);
                /* If we have very few page cache pages,
@@ -1836,8 +1827,23 @@ out:
                        scan >>= priority;
                        scan = div64_u64(scan * fraction[file], denominator);
                }
-               nr[l] = nr_scan_try_batch(scan,
-                                         &reclaim_stat->nr_saved_scan[l]);
+
+               /*
+                * If zone is small or memcg is small, nr[l] can be 0.
+                * This results no-scan on this priority and priority drop down.
+                * For global direct reclaim, it can visit next zone and tend
+                * not to have problems. For global kswapd, it's for zone
+                * balancing and it need to scan a small amounts. When using
+                * memcg, priority drop can cause big latency. So, it's better
+                * to scan small amount. See may_noscan above.
+                */
+               if (!scan && force_scan) {
+                       if (file)
+                               scan = SWAP_CLUSTER_MAX;
+                       else if (!noswap)
+                               scan = SWAP_CLUSTER_MAX;
+               }
+               nr[l] = scan;
        }
 }
 
@@ -1977,11 +1983,14 @@ restart:
  * If a zone is deemed to be full of pinned pages then just give it a light
  * scan then give up on it.
  */
-static void shrink_zones(int priority, struct zonelist *zonelist,
+static unsigned long shrink_zones(int priority, struct zonelist *zonelist,
                                        struct scan_control *sc)
 {
        struct zoneref *z;
        struct zone *zone;
+       unsigned long nr_soft_reclaimed;
+       unsigned long nr_soft_scanned;
+       unsigned long total_scanned = 0;
 
        for_each_zone_zonelist_nodemask(zone, z, zonelist,
                                        gfp_zone(sc->gfp_mask), sc->nodemask) {
@@ -1998,8 +2007,17 @@ static void shrink_zones(int priority, struct zonelist *zonelist,
                                continue;       /* Let kswapd poll it */
                }
 
+               nr_soft_scanned = 0;
+               nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone,
+                                                       sc->order, sc->gfp_mask,
+                                                       &nr_soft_scanned);
+               sc->nr_reclaimed += nr_soft_reclaimed;
+               total_scanned += nr_soft_scanned;
+
                shrink_zone(priority, zone, sc);
        }
+
+       return total_scanned;
 }
 
 static bool zone_reclaimable(struct zone *zone)
@@ -2064,7 +2082,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                sc->nr_scanned = 0;
                if (!priority)
                        disable_swap_token();
-               shrink_zones(priority, zonelist, sc);
+               total_scanned += shrink_zones(priority, zonelist, sc);
                /*
                 * Don't shrink slabs when reclaiming memory from
                 * over limit cgroups
@@ -2171,9 +2189,11 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
 unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
                                                gfp_t gfp_mask, bool noswap,
                                                unsigned int swappiness,
-                                               struct zone *zone)
+                                               struct zone *zone,
+                                               unsigned long *nr_scanned)
 {
        struct scan_control sc = {
+               .nr_scanned = 0,
                .nr_to_reclaim = SWAP_CLUSTER_MAX,
                .may_writepage = !laptop_mode,
                .may_unmap = 1,
@@ -2182,6 +2202,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
                .order = 0,
                .mem_cgroup = mem,
        };
+
        sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
                        (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
 
@@ -2200,6 +2221,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 
        trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed);
 
+       *nr_scanned = sc.nr_scanned;
        return sc.nr_reclaimed;
 }
 
@@ -2210,6 +2232,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 {
        struct zonelist *zonelist;
        unsigned long nr_reclaimed;
+       int nid;
        struct scan_control sc = {
                .may_writepage = !laptop_mode,
                .may_unmap = 1,
@@ -2226,7 +2249,14 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
                .gfp_mask = sc.gfp_mask,
        };
 
-       zonelist = NODE_DATA(numa_node_id())->node_zonelists;
+       /*
+        * Unlike direct reclaim via alloc_pages(), memcg's reclaim doesn't
+        * take care of from where we get pages. So the node where we start the
+        * scan does not need to be the current node.
+        */
+       nid = mem_cgroup_select_victim_node(mem_cont);
+
+       zonelist = NODE_DATA(nid)->node_zonelists;
 
        trace_mm_vmscan_memcg_reclaim_begin(0,
                                            sc.may_writepage,
@@ -2347,6 +2377,8 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
        int end_zone = 0;       /* Inclusive.  0 = ZONE_DMA */
        unsigned long total_scanned;
        struct reclaim_state *reclaim_state = current->reclaim_state;
+       unsigned long nr_soft_reclaimed;
+       unsigned long nr_soft_scanned;
        struct scan_control sc = {
                .gfp_mask = GFP_KERNEL,
                .may_unmap = 1,
@@ -2439,11 +2471,15 @@ loop_again:
 
                        sc.nr_scanned = 0;
 
+                       nr_soft_scanned = 0;
                        /*
                         * Call soft limit reclaim before calling shrink_zone.
-                        * For now we ignore the return value
                         */
-                       mem_cgroup_soft_limit_reclaim(zone, order, sc.gfp_mask);
+                       nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone,
+                                                       order, sc.gfp_mask,
+                                                       &nr_soft_scanned);
+                       sc.nr_reclaimed += nr_soft_reclaimed;
+                       total_scanned += nr_soft_scanned;
 
                        /*
                         * We put equal pressure on every zone, unless