per-zone and reclaim enhancements for memory controller: add scan_global_lru macro
[deliverable/linux.git] / mm / memcontrol.c
index dbf571547c0333f30f6cfdba07bced94f3bf5405..14cb6142ec4c63ee942b5ffe4e4a5f175713fdfc 100644 (file)
@@ -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>
 #include <linux/swap.h>
 #include <linux/spinlock.h>
 #include <linux/fs.h>
+#include <linux/seq_file.h>
 
 #include <asm/uaccess.h>
 
 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 +106,10 @@ struct mem_cgroup {
         */
        spinlock_t lru_lock;
        unsigned long control_type;     /* control RSS or RSS+Pagecache */
+       /*
+        * statistics.
+        */
+       struct mem_cgroup_stat stat;
 };
 
 /*
@@ -86,6 +133,7 @@ struct page_cgroup {
        int      flags;
 };
 #define PAGE_CGROUP_FLAG_CACHE (0x1)   /* charged as cache */
+#define PAGE_CGROUP_FLAG_ACTIVE (0x2)  /* page is active in this cgroup */
 
 enum {
        MEM_CGROUP_TYPE_UNSPEC = 0,
@@ -100,6 +148,24 @@ 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
@@ -174,8 +240,8 @@ 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;
 
@@ -197,8 +263,8 @@ 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 */
@@ -210,13 +276,15 @@ 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)
+       if (active) {
+               pc->flags |= PAGE_CGROUP_FLAG_ACTIVE;
                list_move(&pc->lru, &pc->mem_cgroup->active_list);
-       else
+       } else {
+               pc->flags &= ~PAGE_CGROUP_FLAG_ACTIVE;
                list_move(&pc->lru, &pc->mem_cgroup->inactive_list);
+       }
 }
 
 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
@@ -329,23 +397,26 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
         * with it
         */
 retry:
-       lock_page_cgroup(page);
-       pc = page_get_page_cgroup(page);
-       /*
-        * The page_cgroup exists and the page has already been accounted
-        */
-       if (pc) {
-               if (unlikely(!atomic_inc_not_zero(&pc->ref_cnt))) {
-                       /* this page is under being uncharged ? */
-                       unlock_page_cgroup(page);
-                       cpu_relax();
-                       goto retry;
-               } else {
-                       unlock_page_cgroup(page);
-                       goto done;
+       if (page) {
+               lock_page_cgroup(page);
+               pc = page_get_page_cgroup(page);
+               /*
+                * The page_cgroup exists and
+                * the page has already been accounted.
+                */
+               if (pc) {
+                       if (unlikely(!atomic_inc_not_zero(&pc->ref_cnt))) {
+                               /* this page is under being uncharged ? */
+                               unlock_page_cgroup(page);
+                               cpu_relax();
+                               goto retry;
+                       } else {
+                               unlock_page_cgroup(page);
+                               goto done;
+                       }
                }
+               unlock_page_cgroup(page);
        }
-       unlock_page_cgroup(page);
 
        pc = kzalloc(sizeof(struct page_cgroup), gfp_mask);
        if (pc == NULL)
@@ -400,11 +471,11 @@ retry:
        atomic_set(&pc->ref_cnt, 1);
        pc->mem_cgroup = mem;
        pc->page = page;
-       pc->flags = 0;
+       pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
        if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE)
                pc->flags |= PAGE_CGROUP_FLAG_CACHE;
 
-       if (page_cgroup_assign_new_page_cgroup(page, pc)) {
+       if (!page || page_cgroup_assign_new_page_cgroup(page, pc)) {
                /*
                 * Another charge has been added to this page already.
                 * We take lock_page_cgroup(page) again and read
@@ -413,10 +484,14 @@ retry:
                res_counter_uncharge(&mem->res, PAGE_SIZE);
                css_put(&mem->css);
                kfree(pc);
+               if (!page)
+                       goto done;
                goto 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);
 
@@ -487,6 +562,7 @@ 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);
                }
@@ -563,6 +639,7 @@ 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;
@@ -718,6 +795,49 @@ static ssize_t mem_force_empty_read(struct cgroup *cont,
 }
 
 
+static const struct mem_cgroup_stat_desc {
+       const char *msg;
+       u64 unit;
+} mem_cgroup_stat_desc[] = {
+       [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, },
+       [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
+};
+
+static int mem_control_stat_show(struct seq_file *m, void *arg)
+{
+       struct cgroup *cont = m->private;
+       struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
+       struct mem_cgroup_stat *stat = &mem_cont->stat;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) {
+               s64 val;
+
+               val = mem_cgroup_read_stat(stat, i);
+               val *= mem_cgroup_stat_desc[i].unit;
+               seq_printf(m, "%s %lld\n", mem_cgroup_stat_desc[i].msg,
+                               (long long)val);
+       }
+       return 0;
+}
+
+static const struct file_operations mem_control_stat_file_operations = {
+       .read = seq_read,
+       .llseek = seq_lseek,
+       .release = single_release,
+};
+
+static int mem_control_stat_open(struct inode *unused, struct file *file)
+{
+       /* XXX __d_cont */
+       struct cgroup *cont = file->f_dentry->d_parent->d_fsdata;
+
+       file->f_op = &mem_control_stat_file_operations;
+       return single_open(file, mem_control_stat_show, cont);
+}
+
+
+
 static struct cftype mem_cgroup_files[] = {
        {
                .name = "usage_in_bytes",
@@ -745,6 +865,10 @@ static struct cftype mem_cgroup_files[] = {
                .write = mem_force_empty_write,
                .read = mem_force_empty_read,
        },
+       {
+               .name = "stat",
+               .open = mem_control_stat_open,
+       },
 };
 
 static struct mem_cgroup init_mem_cgroup;
@@ -771,6 +895,13 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
        return &mem->css;
 }
 
+static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
+                                       struct cgroup *cont)
+{
+       struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
+       mem_cgroup_force_empty(mem);
+}
+
 static void mem_cgroup_destroy(struct cgroup_subsys *ss,
                                struct cgroup *cont)
 {
@@ -822,6 +953,7 @@ struct cgroup_subsys mem_cgroup_subsys = {
        .name = "memory",
        .subsys_id = mem_cgroup_subsys_id,
        .create = mem_cgroup_create,
+       .pre_destroy = mem_cgroup_pre_destroy,
        .destroy = mem_cgroup_destroy,
        .populate = mem_cgroup_populate,
        .attach = mem_cgroup_move_task,
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