Merge branch 'master' into for-next

Sync with Linus' tree to be able to apply pending patches that
are based on newer code already present upstream.

1 files changed, 158 insertions, 64 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index bd9052a5d3ad..e013b8e57d25 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -35,6 +35,7 @@
 #include <linux/limits.h>
 #include <linux/mutex.h>
 #include <linux/rbtree.h>
+#include <linux/shmem_fs.h>
 #include <linux/slab.h>
 #include <linux/swap.h>
 #include <linux/swapops.h>
@@ -107,10 +108,12 @@ enum mem_cgroup_events_index {
 enum mem_cgroup_events_target {
         MEM_CGROUP_TARGET_THRESH,
         MEM_CGROUP_TARGET_SOFTLIMIT,
+        MEM_CGROUP_TARGET_NUMAINFO,
         MEM_CGROUP_NTARGETS,
 };
 #define THRESHOLDS_EVENTS_TARGET (128)
 #define SOFTLIMIT_EVENTS_TARGET (1024)
+#define NUMAINFO_EVENTS_TARGET  (1024)
 
 struct mem_cgroup_stat_cpu {
         long count[MEM_CGROUP_STAT_NSTATS];
@@ -236,7 +239,8 @@ struct mem_cgroup {
         int last_scanned_node;
 #if MAX_NUMNODES > 1
         nodemask_t      scan_nodes;
-        unsigned long   next_scan_node_update;
+        atomic_t        numainfo_events;
+        atomic_t        numainfo_updating;
 #endif
         /*
          * Should the accounting and control be hierarchical, per subtree?
@@ -359,7 +363,7 @@ enum charge_type {
 static void mem_cgroup_get(struct mem_cgroup *mem);
 static void mem_cgroup_put(struct mem_cgroup *mem);
 static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
-static void drain_all_stock_async(void);
+static void drain_all_stock_async(struct mem_cgroup *mem);
 
 static struct mem_cgroup_per_zone *
 mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
@@ -576,15 +580,6 @@ static long mem_cgroup_read_stat(struct mem_cgroup *mem,
         return val;
 }
 
-static long mem_cgroup_local_usage(struct mem_cgroup *mem)
-{
-        long ret;
-
-        ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
-        ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
-        return ret;
-}
-
 static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
                                          bool charge)
 {
@@ -688,6 +683,9 @@ static void __mem_cgroup_target_update(struct mem_cgroup *mem, int target)
         case MEM_CGROUP_TARGET_SOFTLIMIT:
                 next = val + SOFTLIMIT_EVENTS_TARGET;
                 break;
+        case MEM_CGROUP_TARGET_NUMAINFO:
+                next = val + NUMAINFO_EVENTS_TARGET;
+                break;
         default:
                 return;
         }
@@ -706,11 +704,19 @@ static void memcg_check_events(struct mem_cgroup *mem, struct page *page)
                 mem_cgroup_threshold(mem);
                 __mem_cgroup_target_update(mem, MEM_CGROUP_TARGET_THRESH);
                 if (unlikely(__memcg_event_check(mem,
-                        MEM_CGROUP_TARGET_SOFTLIMIT))){
+                             MEM_CGROUP_TARGET_SOFTLIMIT))) {
                         mem_cgroup_update_tree(mem, page);
                         __mem_cgroup_target_update(mem,
-                                MEM_CGROUP_TARGET_SOFTLIMIT);
+                                                   MEM_CGROUP_TARGET_SOFTLIMIT);
                 }
+#if MAX_NUMNODES > 1
+                if (unlikely(__memcg_event_check(mem,
+                        MEM_CGROUP_TARGET_NUMAINFO))) {
+                        atomic_inc(&mem->numainfo_events);
+                        __mem_cgroup_target_update(mem,
+                                MEM_CGROUP_TARGET_NUMAINFO);
+                }
+#endif
         }
 }
 
@@ -735,7 +741,7 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
                                 struct mem_cgroup, css);
 }
 
-static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
+struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 {
         struct mem_cgroup *mem = NULL;
 
@@ -1128,7 +1134,6 @@ unsigned long mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg,
         return MEM_CGROUP_ZSTAT(mz, lru);
 }
 
-#ifdef CONFIG_NUMA
 static unsigned long mem_cgroup_node_nr_file_lru_pages(struct mem_cgroup *memcg,
                                                         int nid)
 {
@@ -1140,6 +1145,17 @@ static unsigned long mem_cgroup_node_nr_file_lru_pages(struct mem_cgroup *memcg,
         return ret;
 }
 
+static unsigned long mem_cgroup_node_nr_anon_lru_pages(struct mem_cgroup *memcg,
+                                                        int nid)
+{
+        unsigned long ret;
+
+        ret = mem_cgroup_get_zonestat_node(memcg, nid, LRU_INACTIVE_ANON) +
+                mem_cgroup_get_zonestat_node(memcg, nid, LRU_ACTIVE_ANON);
+        return ret;
+}
+
+#if MAX_NUMNODES > 1
 static unsigned long mem_cgroup_nr_file_lru_pages(struct mem_cgroup *memcg)
 {
         u64 total = 0;
@@ -1151,17 +1167,6 @@ static unsigned long mem_cgroup_nr_file_lru_pages(struct mem_cgroup *memcg)
         return total;
 }
 
-static unsigned long mem_cgroup_node_nr_anon_lru_pages(struct mem_cgroup *memcg,
-                                                        int nid)
-{
-        unsigned long ret;
-
-        ret = mem_cgroup_get_zonestat_node(memcg, nid, LRU_INACTIVE_ANON) +
-                mem_cgroup_get_zonestat_node(memcg, nid, LRU_ACTIVE_ANON);
-
-        return ret;
-}
-
 static unsigned long mem_cgroup_nr_anon_lru_pages(struct mem_cgroup *memcg)
 {
         u64 total = 0;
@@ -1558,6 +1563,28 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem)
         return ret;
 }
 
+/**
+ * test_mem_cgroup_node_reclaimable
+ * @mem: the target memcg
+ * @nid: the node ID to be checked.
+ * @noswap : specify true here if the user wants flle only information.
+ *
+ * This function returns whether the specified memcg contains any
+ * reclaimable pages on a node. Returns true if there are any reclaimable
+ * pages in the node.
+ */
+static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *mem,
+                int nid, bool noswap)
+{
+        if (mem_cgroup_node_nr_file_lru_pages(mem, nid))
+                return true;
+        if (noswap || !total_swap_pages)
+                return false;
+        if (mem_cgroup_node_nr_anon_lru_pages(mem, nid))
+                return true;
+        return false;
+
+}
 #if MAX_NUMNODES > 1
 
 /*
@@ -1569,26 +1596,26 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem)
 static void mem_cgroup_may_update_nodemask(struct mem_cgroup *mem)
 {
         int nid;
-
-        if (time_after(mem->next_scan_node_update, jiffies))
+        /*
+         * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
+         * pagein/pageout changes since the last update.
+         */
+        if (!atomic_read(&mem->numainfo_events))
+                return;
+        if (atomic_inc_return(&mem->numainfo_updating) > 1)
                 return;
 
-        mem->next_scan_node_update = jiffies + 10*HZ;
         /* make a nodemask where this memcg uses memory from */
         mem->scan_nodes = node_states[N_HIGH_MEMORY];
 
         for_each_node_mask(nid, node_states[N_HIGH_MEMORY]) {
 
-                if (mem_cgroup_get_zonestat_node(mem, nid, LRU_INACTIVE_FILE) ||
-                    mem_cgroup_get_zonestat_node(mem, nid, LRU_ACTIVE_FILE))
-                        continue;
-
-                if (total_swap_pages &&
-                    (mem_cgroup_get_zonestat_node(mem, nid, LRU_INACTIVE_ANON) ||
-                     mem_cgroup_get_zonestat_node(mem, nid, LRU_ACTIVE_ANON)))
-                        continue;
-                node_clear(nid, mem->scan_nodes);
+                if (!test_mem_cgroup_node_reclaimable(mem, nid, false))
+                        node_clear(nid, mem->scan_nodes);
         }
+
+        atomic_set(&mem->numainfo_events, 0);
+        atomic_set(&mem->numainfo_updating, 0);
 }
 
 /*
@@ -1626,11 +1653,51 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
         return node;
 }
 
+/*
+ * Check all nodes whether it contains reclaimable pages or not.
+ * For quick scan, we make use of scan_nodes. This will allow us to skip
+ * unused nodes. But scan_nodes is lazily updated and may not cotain
+ * enough new information. We need to do double check.
+ */
+bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
+{
+        int nid;
+
+        /*
+         * quick check...making use of scan_node.
+         * We can skip unused nodes.
+         */
+        if (!nodes_empty(mem->scan_nodes)) {
+                for (nid = first_node(mem->scan_nodes);
+                     nid < MAX_NUMNODES;
+                     nid = next_node(nid, mem->scan_nodes)) {
+
+                        if (test_mem_cgroup_node_reclaimable(mem, nid, noswap))
+                                return true;
+                }
+        }
+        /*
+         * Check rest of nodes.
+         */
+        for_each_node_state(nid, N_HIGH_MEMORY) {
+                if (node_isset(nid, mem->scan_nodes))
+                        continue;
+                if (test_mem_cgroup_node_reclaimable(mem, nid, noswap))
+                        return true;
+        }
+        return false;
+}
+
 #else
 int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
 {
         return 0;
 }
+
+bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
+{
+        return test_mem_cgroup_node_reclaimable(mem, 0, noswap);
+}
 #endif
 
 /*
@@ -1663,15 +1730,21 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
         excess = res_counter_soft_limit_excess(&root_mem->res) >> PAGE_SHIFT;
 
         /* If memsw_is_minimum==1, swap-out is of-no-use. */
-        if (root_mem->memsw_is_minimum)
+        if (!check_soft && root_mem->memsw_is_minimum)
                 noswap = true;
 
         while (1) {
                 victim = mem_cgroup_select_victim(root_mem);
                 if (victim == root_mem) {
                         loop++;
-                        if (loop >= 1)
-                                drain_all_stock_async();
+                        /*
+                         * We are not draining per cpu cached charges during
+                         * soft limit reclaim  because global reclaim doesn't
+                         * care about charges. It tries to free some memory and
+                         * charges will not give any.
+                         */
+                        if (!check_soft && loop >= 1)
+                                drain_all_stock_async(root_mem);
                         if (loop >= 2) {
                                 /*
                                  * If we have not been able to reclaim
@@ -1695,7 +1768,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
                                 }
                         }
                 }
-                if (!mem_cgroup_local_usage(victim)) {
+                if (!mem_cgroup_reclaimable(victim, noswap)) {
                         /* this cgroup's local usage == 0 */
                         css_put(&victim->css);
                         continue;
@@ -1934,9 +2007,11 @@ struct memcg_stock_pcp {
         struct mem_cgroup *cached; /* this never be root cgroup */
         unsigned int nr_pages;
         struct work_struct work;
+        unsigned long flags;
+#define FLUSHING_CACHED_CHARGE  (0)
 };
 static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
-static atomic_t memcg_drain_count;
+static DEFINE_MUTEX(percpu_charge_mutex);
 
 /*
  * Try to consume stocked charge on this cpu. If success, one page is consumed
@@ -1984,6 +2059,7 @@ static void drain_local_stock(struct work_struct *dummy)
 {
         struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
         drain_stock(stock);
+        clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
 }
 
 /*
@@ -2008,26 +2084,45 @@ static void refill_stock(struct mem_cgroup *mem, unsigned int nr_pages)
  * expects some charges will be back to res_counter later but cannot wait for
  * it.
  */
-static void drain_all_stock_async(void)
+static void drain_all_stock_async(struct mem_cgroup *root_mem)
 {
-        int cpu;
-        /* This function is for scheduling "drain" in asynchronous way.
-         * The result of "drain" is not directly handled by callers. Then,
-         * if someone is calling drain, we don't have to call drain more.
-         * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
-         * there is a race. We just do loose check here.
+        int cpu, curcpu;
+        /*
+         * If someone calls draining, avoid adding more kworker runs.
          */
-        if (atomic_read(&memcg_drain_count))
+        if (!mutex_trylock(&percpu_charge_mutex))
                 return;
         /* Notify other cpus that system-wide "drain" is running */
-        atomic_inc(&memcg_drain_count);
         get_online_cpus();
+        /*
+         * Get a hint for avoiding draining charges on the current cpu,
+         * which must be exhausted by our charging.  It is not required that
+         * this be a precise check, so we use raw_smp_processor_id() instead of
+         * getcpu()/putcpu().
+         */
+        curcpu = raw_smp_processor_id();
         for_each_online_cpu(cpu) {
                 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
-                schedule_work_on(cpu, &stock->work);
+                struct mem_cgroup *mem;
+
+                if (cpu == curcpu)
+                        continue;
+
+                mem = stock->cached;
+                if (!mem)
+                        continue;
+                if (mem != root_mem) {
+                        if (!root_mem->use_hierarchy)
+                                continue;
+                        /* check whether "mem" is under tree of "root_mem" */
+                        if (!css_is_ancestor(&mem->css, &root_mem->css))
+                                continue;
+                }
+                if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags))
+                        schedule_work_on(cpu, &stock->work);
         }
         put_online_cpus();
-        atomic_dec(&memcg_drain_count);
+        mutex_unlock(&percpu_charge_mutex);
         /* We don't wait for flush_work */
 }
 
@@ -2035,9 +2130,9 @@ static void drain_all_stock_async(void)
 static void drain_all_stock_sync(void)
 {
         /* called when force_empty is called */
-        atomic_inc(&memcg_drain_count);
+        mutex_lock(&percpu_charge_mutex);
         schedule_on_each_cpu(drain_local_stock);
-        atomic_dec(&memcg_drain_count);
+        mutex_unlock(&percpu_charge_mutex);
 }
 
 /*
@@ -4640,6 +4735,7 @@ static struct cftype mem_cgroup_files[] = {
         {
                 .name = "numa_stat",
                 .open = mem_control_numa_stat_open,
+                .mode = S_IRUGO,
         },
 #endif
 };
@@ -5414,18 +5510,16 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss,
                                 struct cgroup *old_cont,
                                 struct task_struct *p)
 {
-        struct mm_struct *mm;
+        struct mm_struct *mm = get_task_mm(p);
 
-        if (!mc.to)
-                /* no need to move charge */
-                return;
-
-        mm = get_task_mm(p);
         if (mm) {
-                mem_cgroup_move_charge(mm);
+                if (mc.to)
+                        mem_cgroup_move_charge(mm);
+                put_swap_token(mm);
                 mmput(mm);
         }
-        mem_cgroup_clear_mc();
+        if (mc.to)
+                mem_cgroup_clear_mc();
 }
 #else   /* !CONFIG_MMU */
 static int mem_cgroup_can_attach(struct cgroup_subsys *ss,