memory cgroup enhancements: add status accounting function for memory cgroup

[mirror_ubuntu-zesty-kernel.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 31c4f0cefdeef5eb2f71b855a37566c2c603ee4d..5f3ad9c37bea8c3a2d3a478723f8e435a753f545 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -21,6 +21,7 @@
 #include <linux/memcontrol.h>
 #include <linux/cgroup.h>
 #include <linux/mm.h>
+#include <linux/smp.h>
 #include <linux/page-flags.h>
 #include <linux/backing-dev.h>
 #include <linux/bit_spinlock.h>
@@ -34,6 +35,47 @@
 struct cgroup_subsys mem_cgroup_subsys;
 static const int MEM_CGROUP_RECLAIM_RETRIES = 5;
 
+/*
+ * Statistics for memory cgroup.
+ */
+enum mem_cgroup_stat_index {
+       /*
+        * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
+        */
+       MEM_CGROUP_STAT_CACHE,     /* # of pages charged as cache */
+       MEM_CGROUP_STAT_RSS,       /* # of pages charged as rss */
+
+       MEM_CGROUP_STAT_NSTATS,
+};
+
+struct mem_cgroup_stat_cpu {
+       s64 count[MEM_CGROUP_STAT_NSTATS];
+} ____cacheline_aligned_in_smp;
+
+struct mem_cgroup_stat {
+       struct mem_cgroup_stat_cpu cpustat[NR_CPUS];
+};
+
+/*
+ * For accounting under irq disable, no need for increment preempt count.
+ */
+static void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat *stat,
+               enum mem_cgroup_stat_index idx, int val)
+{
+       int cpu = smp_processor_id();
+       stat->cpustat[cpu].count[idx] += val;
+}
+
+static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
+               enum mem_cgroup_stat_index idx)
+{
+       int cpu;
+       s64 ret = 0;
+       for_each_possible_cpu(cpu)
+               ret += stat->cpustat[cpu].count[idx];
+       return ret;
+}
+
 /*
  * The memory controller data structure. The memory controller controls both
  * page cache and RSS per cgroup. We would eventually like to provide
@@ -63,6 +105,10 @@ struct mem_cgroup {
         */
        spinlock_t lru_lock;
        unsigned long control_type;     /* control RSS or RSS+Pagecache */
+       /*
+        * statistics.
+        */
+       struct mem_cgroup_stat stat;
 };
 
 /*
@@ -101,6 +147,24 @@ enum charge_type {
        MEM_CGROUP_CHARGE_TYPE_MAPPED,
 };
 
+/*
+ * Always modified under lru lock. Then, not necessary to preempt_disable()
+ */
+static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, int flags,
+                                       bool charge)
+{
+       int val = (charge)? 1 : -1;
+       struct mem_cgroup_stat *stat = &mem->stat;
+       VM_BUG_ON(!irqs_disabled());
+
+       if (flags & PAGE_CGROUP_FLAG_CACHE)
+               __mem_cgroup_stat_add_safe(stat,
+                                       MEM_CGROUP_STAT_CACHE, val);
+       else
+               __mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_RSS, val);
+
+}
+
 static struct mem_cgroup init_mem_cgroup;
 
 static inline
@@ -175,8 +239,8 @@ static void __always_inline unlock_page_cgroup(struct page *page)
  * This can fail if the page has been tied to a page_cgroup.
  * If success, returns 0.
  */
-static inline int
-page_cgroup_assign_new_page_cgroup(struct page *page, struct page_cgroup *pc)
+static int page_cgroup_assign_new_page_cgroup(struct page *page,
+                                               struct page_cgroup *pc)
 {
        int ret = 0;
 
@@ -198,8 +262,8 @@ page_cgroup_assign_new_page_cgroup(struct page *page, struct page_cgroup *pc)
  *  clear_page_cgroup(page, pc) == pc
  */
 
-static inline struct page_cgroup *
-clear_page_cgroup(struct page *page, struct page_cgroup *pc)
+static struct page_cgroup *clear_page_cgroup(struct page *page,
+                                               struct page_cgroup *pc)
 {
        struct page_cgroup *ret;
        /* lock and clear */
@@ -211,7 +275,6 @@ clear_page_cgroup(struct page *page, struct page_cgroup *pc)
        return ret;
 }
 
-
 static void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
 {
        if (active) {
@@ -426,6 +489,8 @@ retry:
        }
 
        spin_lock_irqsave(&mem->lru_lock, flags);
+       /* Update statistics vector */
+       mem_cgroup_charge_statistics(mem, pc->flags, true);
        list_add(&pc->lru, &mem->active_list);
        spin_unlock_irqrestore(&mem->lru_lock, flags);
 
@@ -496,6 +561,7 @@ void mem_cgroup_uncharge(struct page_cgroup *pc)
                        res_counter_uncharge(&mem->res, PAGE_SIZE);
                        spin_lock_irqsave(&mem->lru_lock, flags);
                        list_del_init(&pc->lru);
+                       mem_cgroup_charge_statistics(mem, pc->flags, false);
                        spin_unlock_irqrestore(&mem->lru_lock, flags);
                        kfree(pc);
                }
@@ -572,6 +638,7 @@ retry:
                        css_put(&mem->css);
                        res_counter_uncharge(&mem->res, PAGE_SIZE);
                        list_del_init(&pc->lru);
+                       mem_cgroup_charge_statistics(mem, pc->flags, false);
                        kfree(pc);
                } else  /* being uncharged ? ...do relax */
                        break;