1 files changed, 13 insertions, 185 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 930de9437271..3508777837c7 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -204,50 +204,6 @@ struct mem_cgroup_eventfd_list {
 static void mem_cgroup_threshold(struct mem_cgroup *mem);
 static void mem_cgroup_oom_notify(struct mem_cgroup *mem);
 
-enum {
-        SCAN_BY_LIMIT,
-        SCAN_BY_SYSTEM,
-        NR_SCAN_CONTEXT,
-        SCAN_BY_SHRINK, /* not recorded now */
-};
-
-enum {
-        SCAN,
-        SCAN_ANON,
-        SCAN_FILE,
-        ROTATE,
-        ROTATE_ANON,
-        ROTATE_FILE,
-        FREED,
-        FREED_ANON,
-        FREED_FILE,
-        ELAPSED,
-        NR_SCANSTATS,
-};
-
-struct scanstat {
-        spinlock_t      lock;
-        unsigned long   stats[NR_SCAN_CONTEXT][NR_SCANSTATS];
-        unsigned long   rootstats[NR_SCAN_CONTEXT][NR_SCANSTATS];
-};
-
-const char *scanstat_string[NR_SCANSTATS] = {
-        "scanned_pages",
-        "scanned_anon_pages",
-        "scanned_file_pages",
-        "rotated_pages",
-        "rotated_anon_pages",
-        "rotated_file_pages",
-        "freed_pages",
-        "freed_anon_pages",
-        "freed_file_pages",
-        "elapsed_ns",
-};
-#define SCANSTAT_WORD_LIMIT     "_by_limit"
-#define SCANSTAT_WORD_SYSTEM    "_by_system"
-#define SCANSTAT_WORD_HIERARCHY "_under_hierarchy"
-
-
 /*
  * The memory controller data structure. The memory controller controls both
  * page cache and RSS per cgroup. We would eventually like to provide
@@ -313,8 +269,7 @@ struct mem_cgroup {
 
         /* For oom notifier event fd */
         struct list_head oom_notify;
-        /* For recording LRU-scan statistics */
-        struct scanstat scanstat;
+
         /*
          * Should we move charges of a task when a task is moved into this
          * mem_cgroup ? And what type of charges should we move ?
@@ -1678,44 +1633,6 @@ bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
 }
 #endif
 
-static void __mem_cgroup_record_scanstat(unsigned long *stats,
-                           struct memcg_scanrecord *rec)
-{
-
-        stats[SCAN] += rec->nr_scanned[0] + rec->nr_scanned[1];
-        stats[SCAN_ANON] += rec->nr_scanned[0];
-        stats[SCAN_FILE] += rec->nr_scanned[1];
-
-        stats[ROTATE] += rec->nr_rotated[0] + rec->nr_rotated[1];
-        stats[ROTATE_ANON] += rec->nr_rotated[0];
-        stats[ROTATE_FILE] += rec->nr_rotated[1];
-
-        stats[FREED] += rec->nr_freed[0] + rec->nr_freed[1];
-        stats[FREED_ANON] += rec->nr_freed[0];
-        stats[FREED_FILE] += rec->nr_freed[1];
-
-        stats[ELAPSED] += rec->elapsed;
-}
-
-static void mem_cgroup_record_scanstat(struct memcg_scanrecord *rec)
-{
-        struct mem_cgroup *mem;
-        int context = rec->context;
-
-        if (context >= NR_SCAN_CONTEXT)
-                return;
-
-        mem = rec->mem;
-        spin_lock(&mem->scanstat.lock);
-        __mem_cgroup_record_scanstat(mem->scanstat.stats[context], rec);
-        spin_unlock(&mem->scanstat.lock);
-
-        mem = rec->root;
-        spin_lock(&mem->scanstat.lock);
-        __mem_cgroup_record_scanstat(mem->scanstat.rootstats[context], rec);
-        spin_unlock(&mem->scanstat.lock);
-}
-
 /*
  * Scan the hierarchy if needed to reclaim memory. We remember the last child
  * we reclaimed from, so that we don't end up penalizing one child extensively
@@ -1740,9 +1657,8 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
         bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
         bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
         bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
-        struct memcg_scanrecord rec;
         unsigned long excess;
-        unsigned long scanned;
+        unsigned long nr_scanned;
 
         excess = res_counter_soft_limit_excess(&root_mem->res) >> PAGE_SHIFT;
 
@@ -1750,15 +1666,6 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
         if (!check_soft && !shrink && root_mem->memsw_is_minimum)
                 noswap = true;
 
-        if (shrink)
-                rec.context = SCAN_BY_SHRINK;
-        else if (check_soft)
-                rec.context = SCAN_BY_SYSTEM;
-        else
-                rec.context = SCAN_BY_LIMIT;
-
-        rec.root = root_mem;
-
         while (1) {
                 victim = mem_cgroup_select_victim(root_mem);
                 if (victim == root_mem) {
@@ -1799,23 +1706,14 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
                         css_put(&victim->css);
                         continue;
                 }
-                rec.mem = victim;
-                rec.nr_scanned[0] = 0;
-                rec.nr_scanned[1] = 0;
-                rec.nr_rotated[0] = 0;
-                rec.nr_rotated[1] = 0;
-                rec.nr_freed[0] = 0;
-                rec.nr_freed[1] = 0;
-                rec.elapsed = 0;
                 /* we use swappiness of local cgroup */
                 if (check_soft) {
                         ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
-                                noswap, zone, &rec, &scanned);
-                        *total_scanned += scanned;
+                                noswap, zone, &nr_scanned);
+                        *total_scanned += nr_scanned;
                 } else
                         ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
-                                                noswap, &rec);
-                mem_cgroup_record_scanstat(&rec);
+                                                noswap);
                 css_put(&victim->css);
                 /*
                  * At shrinking usage, we can't check we should stop here or
@@ -1841,29 +1739,23 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
  */
 static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
 {
-        int lock_count = -1;
         struct mem_cgroup *iter, *failed = NULL;
         bool cond = true;
 
         for_each_mem_cgroup_tree_cond(iter, mem, cond) {
-                bool locked = iter->oom_lock;
-
-                iter->oom_lock = true;
-                if (lock_count == -1)
-                        lock_count = iter->oom_lock;
-                else if (lock_count != locked) {
+                if (iter->oom_lock) {
                         /*
                          * this subtree of our hierarchy is already locked
                          * so we cannot give a lock.
                          */
-                        lock_count = 0;
                         failed = iter;
                         cond = false;
-                }
+                } else
+                        iter->oom_lock = true;
         }
 
         if (!failed)
-                goto done;
+                return true;
 
         /*
          * OK, we failed to lock the whole subtree so we have to clean up
@@ -1877,8 +1769,7 @@ static bool mem_cgroup_oom_lock(struct mem_cgroup *mem)
                 }
                 iter->oom_lock = false;
         }
-done:
-        return lock_count;
+        return false;
 }
 
 /*
@@ -2169,13 +2060,7 @@ static void drain_all_stock(struct mem_cgroup *root_mem, bool sync)
 
         /* Notify other cpus that system-wide "drain" is running */
         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();
+        curcpu = get_cpu();
         for_each_online_cpu(cpu) {
                 struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
                 struct mem_cgroup *mem;
@@ -2192,6 +2077,7 @@ static void drain_all_stock(struct mem_cgroup *root_mem, bool sync)
                                 schedule_work_on(cpu, &stock->work);
                 }
         }
+        put_cpu();
 
         if (!sync)
                 goto out;
@@ -3866,18 +3752,14 @@ try_to_free:
         /* try to free all pages in this cgroup */
         shrink = 1;
         while (nr_retries && mem->res.usage > 0) {
-                struct memcg_scanrecord rec;
                 int progress;
 
                 if (signal_pending(current)) {
                         ret = -EINTR;
                         goto out;
                 }
-                rec.context = SCAN_BY_SHRINK;
-                rec.mem = mem;
-                rec.root = mem;
                 progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
-                                                false, &rec);
+                                                false);
                 if (!progress) {
                         nr_retries--;
                         /* maybe some writeback is necessary */
@@ -4721,54 +4603,6 @@ static int mem_control_numa_stat_open(struct inode *unused, struct file *file)
 }
 #endif /* CONFIG_NUMA */
 
-static int mem_cgroup_vmscan_stat_read(struct cgroup *cgrp,
-                                struct cftype *cft,
-                                struct cgroup_map_cb *cb)
-{
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
-        char string[64];
-        int i;
-
-        for (i = 0; i < NR_SCANSTATS; i++) {
-                strcpy(string, scanstat_string[i]);
-                strcat(string, SCANSTAT_WORD_LIMIT);
-                cb->fill(cb, string,  mem->scanstat.stats[SCAN_BY_LIMIT][i]);
-        }
-
-        for (i = 0; i < NR_SCANSTATS; i++) {
-                strcpy(string, scanstat_string[i]);
-                strcat(string, SCANSTAT_WORD_SYSTEM);
-                cb->fill(cb, string,  mem->scanstat.stats[SCAN_BY_SYSTEM][i]);
-        }
-
-        for (i = 0; i < NR_SCANSTATS; i++) {
-                strcpy(string, scanstat_string[i]);
-                strcat(string, SCANSTAT_WORD_LIMIT);
-                strcat(string, SCANSTAT_WORD_HIERARCHY);
-                cb->fill(cb, string,  mem->scanstat.rootstats[SCAN_BY_LIMIT][i]);
-        }
-        for (i = 0; i < NR_SCANSTATS; i++) {
-                strcpy(string, scanstat_string[i]);
-                strcat(string, SCANSTAT_WORD_SYSTEM);
-                strcat(string, SCANSTAT_WORD_HIERARCHY);
-                cb->fill(cb, string,  mem->scanstat.rootstats[SCAN_BY_SYSTEM][i]);
-        }
-        return 0;
-}
-
-static int mem_cgroup_reset_vmscan_stat(struct cgroup *cgrp,
-                                unsigned int event)
-{
-        struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
-
-        spin_lock(&mem->scanstat.lock);
-        memset(&mem->scanstat.stats, 0, sizeof(mem->scanstat.stats));
-        memset(&mem->scanstat.rootstats, 0, sizeof(mem->scanstat.rootstats));
-        spin_unlock(&mem->scanstat.lock);
-        return 0;
-}
-
-
 static struct cftype mem_cgroup_files[] = {
         {
                 .name = "usage_in_bytes",
@@ -4839,11 +4673,6 @@ static struct cftype mem_cgroup_files[] = {
                 .mode = S_IRUGO,
         },
 #endif
-        {
-                .name = "vmscan_stat",
-                .read_map = mem_cgroup_vmscan_stat_read,
-                .trigger = mem_cgroup_reset_vmscan_stat,
-        },
 };
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
@@ -5107,7 +4936,6 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
         atomic_set(&mem->refcnt, 1);
         mem->move_charge_at_immigrate = 0;
         mutex_init(&mem->thresholds_lock);
-        spin_lock_init(&mem->scanstat.lock);
         return &mem->css;
 free_out:
         __mem_cgroup_free(mem);