pandora: update defconfig
[pandora-kernel.git] / mm / vmscan.c
index f2c367c..9c7e57c 100644 (file)
@@ -73,10 +73,14 @@ struct scan_control {
 
        int swappiness;
 
-       int all_unreclaimable;
-
        int order;
 
+       /*
+        * Intend to reclaim enough contenious memory rather than to reclaim
+        * enough amount memory. I.e, it's the mode for high order allocation.
+        */
+       bool lumpy_reclaim_mode;
+
        /* Which cgroup do we reclaim from */
        struct mem_cgroup *mem_cgroup;
 
@@ -85,12 +89,6 @@ struct scan_control {
         * are scanned.
         */
        nodemask_t      *nodemask;
-
-       /* Pluggable isolate pages callback */
-       unsigned long (*isolate_pages)(unsigned long nr, struct list_head *dst,
-                       unsigned long *scanned, int order, int mode,
-                       struct zone *z, struct mem_cgroup *mem_cont,
-                       int active, int file);
 };
 
 #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
@@ -575,7 +573,7 @@ static enum page_references page_check_references(struct page *page,
        referenced_page = TestClearPageReferenced(page);
 
        /* Lumpy reclaim - ignore references */
-       if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
+       if (sc->lumpy_reclaim_mode)
                return PAGEREF_RECLAIM;
 
        /*
@@ -839,11 +837,6 @@ keep:
        return nr_reclaimed;
 }
 
-/* LRU Isolation modes. */
-#define ISOLATE_INACTIVE 0     /* Isolate inactive pages. */
-#define ISOLATE_ACTIVE 1       /* Isolate active pages. */
-#define ISOLATE_BOTH 2         /* Isolate both active and inactive pages. */
-
 /*
  * Attempt to remove the specified page from its LRU.  Only take this page
  * if it is of the appropriate PageActive status.  Pages which are being
@@ -1011,7 +1004,6 @@ static unsigned long isolate_pages_global(unsigned long nr,
                                        struct list_head *dst,
                                        unsigned long *scanned, int order,
                                        int mode, struct zone *z,
-                                       struct mem_cgroup *mem_cont,
                                        int active, int file)
 {
        int lru = LRU_BASE;
@@ -1130,7 +1122,6 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
        unsigned long nr_scanned = 0;
        unsigned long nr_reclaimed = 0;
        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(BLK_RW_ASYNC, HZ/10);
@@ -1140,17 +1131,6 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                        return SWAP_CLUSTER_MAX;
        }
 
-       /*
-        * If we need a large contiguous chunk of memory, or have
-        * trouble getting a small set of contiguous pages, we
-        * will reclaim both active and inactive pages.
-        *
-        * We use the same threshold as pageout congestion_wait below.
-        */
-       if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
-               lumpy_reclaim = 1;
-       else if (sc->order && priority < DEF_PRIORITY - 2)
-               lumpy_reclaim = 1;
 
        pagevec_init(&pvec, 1);
 
@@ -1163,15 +1143,15 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                unsigned long nr_freed;
                unsigned long nr_active;
                unsigned int count[NR_LRU_LISTS] = { 0, };
-               int mode = lumpy_reclaim ? ISOLATE_BOTH : ISOLATE_INACTIVE;
+               int mode = sc->lumpy_reclaim_mode ? ISOLATE_BOTH : ISOLATE_INACTIVE;
                unsigned long nr_anon;
                unsigned long nr_file;
 
-               nr_taken = sc->isolate_pages(SWAP_CLUSTER_MAX,
-                            &page_list, &nr_scan, sc->order, mode,
-                               zone, sc->mem_cgroup, 0, file);
-
                if (scanning_global_lru(sc)) {
+                       nr_taken = isolate_pages_global(SWAP_CLUSTER_MAX,
+                                                       &page_list, &nr_scan,
+                                                       sc->order, mode,
+                                                       zone, 0, file);
                        zone->pages_scanned += nr_scan;
                        if (current_is_kswapd())
                                __count_zone_vm_events(PGSCAN_KSWAPD, zone,
@@ -1179,6 +1159,16 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                        else
                                __count_zone_vm_events(PGSCAN_DIRECT, zone,
                                                       nr_scan);
+               } else {
+                       nr_taken = mem_cgroup_isolate_pages(SWAP_CLUSTER_MAX,
+                                                       &page_list, &nr_scan,
+                                                       sc->order, mode,
+                                                       zone, sc->mem_cgroup,
+                                                       0, file);
+                       /*
+                        * mem_cgroup_isolate_pages() keeps track of
+                        * scanned pages on its own.
+                        */
                }
 
                if (nr_taken == 0)
@@ -1216,7 +1206,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                 * but that should be acceptable to the caller
                 */
                if (nr_freed < nr_taken && !current_is_kswapd() &&
-                   lumpy_reclaim) {
+                   sc->lumpy_reclaim_mode) {
                        congestion_wait(BLK_RW_ASYNC, HZ/10);
 
                        /*
@@ -1356,16 +1346,23 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 
        lru_add_drain();
        spin_lock_irq(&zone->lru_lock);
-       nr_taken = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order,
-                                       ISOLATE_ACTIVE, zone,
-                                       sc->mem_cgroup, 1, file);
-       /*
-        * zone->pages_scanned is used for detect zone's oom
-        * mem_cgroup remembers nr_scan by itself.
-        */
        if (scanning_global_lru(sc)) {
+               nr_taken = isolate_pages_global(nr_pages, &l_hold,
+                                               &pgscanned, sc->order,
+                                               ISOLATE_ACTIVE, zone,
+                                               1, file);
                zone->pages_scanned += pgscanned;
+       } else {
+               nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
+                                               &pgscanned, sc->order,
+                                               ISOLATE_ACTIVE, zone,
+                                               sc->mem_cgroup, 1, file);
+               /*
+                * mem_cgroup_isolate_pages() keeps track of
+                * scanned pages on its own.
+                */
        }
+
        reclaim_stat->recent_scanned[file] += nr_taken;
 
        __count_zone_vm_events(PGREFILL, zone, pgscanned);
@@ -1518,22 +1515,53 @@ 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
  * by looking at the fraction of the pages scanned we did rotate back
  * onto the active list instead of evict.
  *
- * percent[0] specifies how much pressure to put on ram/swap backed
- * memory, while percent[1] determines pressure on the file LRUs.
+ * nr[0] = anon pages to scan; nr[1] = file pages to scan
  */
-static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
-                                       unsigned long *percent)
+static void get_scan_count(struct zone *zone, struct scan_control *sc,
+                                       unsigned long *nr, int priority)
 {
        unsigned long anon, file, free;
        unsigned long anon_prio, file_prio;
        unsigned long ap, fp;
        struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+       u64 fraction[2], denominator;
+       enum lru_list l;
+       int noswap = 0;
+
+       /* If we have no swap space, do not bother scanning anon pages. */
+       if (!sc->may_swap || (nr_swap_pages <= 0)) {
+               noswap = 1;
+               fraction[0] = 0;
+               fraction[1] = 1;
+               denominator = 1;
+               goto out;
+       }
 
        anon  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
                zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
@@ -1545,9 +1573,10 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
                /* If we have very few page cache pages,
                   force-scan anon pages. */
                if (unlikely(file + free <= high_wmark_pages(zone))) {
-                       percent[0] = 100;
-                       percent[1] = 0;
-                       return;
+                       fraction[0] = 1;
+                       fraction[1] = 0;
+                       denominator = 1;
+                       goto out;
                }
        }
 
@@ -1594,29 +1623,37 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
        fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1);
        fp /= reclaim_stat->recent_rotated[1] + 1;
 
-       /* Normalize to percentages */
-       percent[0] = 100 * ap / (ap + fp + 1);
-       percent[1] = 100 - percent[0];
+       fraction[0] = ap;
+       fraction[1] = fp;
+       denominator = ap + fp + 1;
+out:
+       for_each_evictable_lru(l) {
+               int file = is_file_lru(l);
+               unsigned long scan;
+
+               scan = zone_nr_lru_pages(zone, sc, l);
+               if (priority || noswap) {
+                       scan >>= priority;
+                       scan = div64_u64(scan * fraction[file], denominator);
+               }
+               nr[l] = nr_scan_try_batch(scan,
+                                         &reclaim_stat->nr_saved_scan[l]);
+       }
 }
 
-/*
- * 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)
+static void set_lumpy_reclaim_mode(int priority, struct scan_control *sc)
 {
-       unsigned long nr;
-
-       *nr_saved_scan += nr_to_scan;
-       nr = *nr_saved_scan;
-
-       if (nr >= SWAP_CLUSTER_MAX)
-               *nr_saved_scan = 0;
+       /*
+        * If we need a large contiguous chunk of memory, or have
+        * trouble getting a small set of contiguous pages, we
+        * will reclaim both active and inactive pages.
+        */
+       if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
+               sc->lumpy_reclaim_mode = 1;
+       else if (sc->order && priority < DEF_PRIORITY - 2)
+               sc->lumpy_reclaim_mode = 1;
        else
-               nr = 0;
-
-       return nr;
+               sc->lumpy_reclaim_mode = 0;
 }
 
 /*
@@ -1627,33 +1664,13 @@ static void shrink_zone(int priority, struct zone *zone,
 {
        unsigned long nr[NR_LRU_LISTS];
        unsigned long nr_to_scan;
-       unsigned long percent[2];       /* anon @ 0; file @ 1 */
        enum lru_list l;
        unsigned long nr_reclaimed = sc->nr_reclaimed;
        unsigned long nr_to_reclaim = sc->nr_to_reclaim;
-       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. */
-       if (!sc->may_swap || (nr_swap_pages <= 0)) {
-               noswap = 1;
-               percent[0] = 0;
-               percent[1] = 100;
-       } else
-               get_scan_ratio(zone, sc, percent);
 
-       for_each_evictable_lru(l) {
-               int file = is_file_lru(l);
-               unsigned long scan;
+       get_scan_count(zone, sc, nr, priority);
 
-               scan = zone_nr_lru_pages(zone, sc, l);
-               if (priority || noswap) {
-                       scan >>= priority;
-                       scan = (scan * percent[file]) / 100;
-               }
-               nr[l] = nr_scan_try_batch(scan,
-                                         &reclaim_stat->nr_saved_scan[l]);
-       }
+       set_lumpy_reclaim_mode(priority, sc);
 
        while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
                                        nr[LRU_INACTIVE_FILE]) {
@@ -1707,14 +1724,14 @@ static void shrink_zone(int priority, struct zone *zone,
  * 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 bool shrink_zones(int priority, struct zonelist *zonelist,
                                        struct scan_control *sc)
 {
        enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask);
        struct zoneref *z;
        struct zone *zone;
+       bool all_unreclaimable = true;
 
-       sc->all_unreclaimable = 1;
        for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx,
                                        sc->nodemask) {
                if (!populated_zone(zone))
@@ -1730,19 +1747,19 @@ static void shrink_zones(int priority, struct zonelist *zonelist,
 
                        if (zone->all_unreclaimable && priority != DEF_PRIORITY)
                                continue;       /* Let kswapd poll it */
-                       sc->all_unreclaimable = 0;
                } else {
                        /*
                         * Ignore cpuset limitation here. We just want to reduce
                         * # of used pages by us regardless of memory shortage.
                         */
-                       sc->all_unreclaimable = 0;
                        mem_cgroup_note_reclaim_priority(sc->mem_cgroup,
                                                        priority);
                }
 
                shrink_zone(priority, zone, sc);
+               all_unreclaimable = false;
        }
+       return all_unreclaimable;
 }
 
 /*
@@ -1765,7 +1782,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                                        struct scan_control *sc)
 {
        int priority;
-       unsigned long ret = 0;
+       bool all_unreclaimable;
        unsigned long total_scanned = 0;
        struct reclaim_state *reclaim_state = current->reclaim_state;
        unsigned long lru_pages = 0;
@@ -1796,7 +1813,7 @@ 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);
+               all_unreclaimable = shrink_zones(priority, zonelist, sc);
                /*
                 * Don't shrink slabs when reclaiming memory from
                 * over limit cgroups
@@ -1809,10 +1826,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                        }
                }
                total_scanned += sc->nr_scanned;
-               if (sc->nr_reclaimed >= sc->nr_to_reclaim) {
-                       ret = sc->nr_reclaimed;
+               if (sc->nr_reclaimed >= sc->nr_to_reclaim)
                        goto out;
-               }
 
                /*
                 * Try to write back as many pages as we just scanned.  This
@@ -1832,9 +1847,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                    priority < DEF_PRIORITY - 2)
                        congestion_wait(BLK_RW_ASYNC, HZ/10);
        }
-       /* top priority shrink_zones still had more to do? don't OOM, then */
-       if (!sc->all_unreclaimable && scanning_global_lru(sc))
-               ret = sc->nr_reclaimed;
+
 out:
        /*
         * Now that we've scanned all the zones at this priority level, note
@@ -1860,7 +1873,14 @@ out:
        delayacct_freepages_end();
        put_mems_allowed();
 
-       return ret;
+       if (sc->nr_reclaimed)
+               return sc->nr_reclaimed;
+
+       /* top priority shrink_zones still had more to do? don't OOM, then */
+       if (scanning_global_lru(sc) && !all_unreclaimable)
+               return 1;
+
+       return 0;
 }
 
 unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
@@ -1875,7 +1895,6 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
                .swappiness = vm_swappiness,
                .order = order,
                .mem_cgroup = NULL,
-               .isolate_pages = isolate_pages_global,
                .nodemask = nodemask,
        };
 
@@ -1896,7 +1915,6 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
                .swappiness = swappiness,
                .order = 0,
                .mem_cgroup = mem,
-               .isolate_pages = mem_cgroup_isolate_pages,
        };
        nodemask_t nm  = nodemask_of_node(nid);
 
@@ -1930,7 +1948,6 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
                .swappiness = swappiness,
                .order = 0,
                .mem_cgroup = mem_cont,
-               .isolate_pages = mem_cgroup_isolate_pages,
                .nodemask = NULL, /* we don't care the placement */
        };
 
@@ -2008,7 +2025,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order)
                .swappiness = vm_swappiness,
                .order = order,
                .mem_cgroup = NULL,
-               .isolate_pages = isolate_pages_global,
        };
        /*
         * temp_priority is used to remember the scanning priority at which
@@ -2387,7 +2403,6 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
                .hibernation_mode = 1,
                .swappiness = vm_swappiness,
                .order = 0,
-               .isolate_pages = isolate_pages_global,
        };
        struct zonelist * zonelist = node_zonelist(numa_node_id(), sc.gfp_mask);
        struct task_struct *p = current;
@@ -2572,7 +2587,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
                .gfp_mask = gfp_mask,
                .swappiness = vm_swappiness,
                .order = order,
-               .isolate_pages = isolate_pages_global,
        };
        unsigned long slab_reclaimable;