mm: memcg: print statistics from live counters

Directly print statistics and event counters instead of going through an
intermediate accumulation stage into a separate array, which used to
require defining statistic items in more than one place.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 66 insertions, 102 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1118e02a40b6..35e008e25422 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -91,6 +91,13 @@ enum mem_cgroup_stat_index {
         MEM_CGROUP_STAT_NSTATS,
 };
 
+static const char * const mem_cgroup_stat_names[] = {
+        "cache",
+        "rss",
+        "mapped_file",
+        "swap",
+};
+
 enum mem_cgroup_events_index {
         MEM_CGROUP_EVENTS_PGPGIN,       /* # of pages paged in */
         MEM_CGROUP_EVENTS_PGPGOUT,      /* # of pages paged out */
@@ -98,6 +105,14 @@ enum mem_cgroup_events_index {
         MEM_CGROUP_EVENTS_PGMAJFAULT,   /* # of major page-faults */
         MEM_CGROUP_EVENTS_NSTATS,
 };
+
+static const char * const mem_cgroup_events_names[] = {
+        "pgpgin",
+        "pgpgout",
+        "pgfault",
+        "pgmajfault",
+};
+
 /*
  * Per memcg event counter is incremented at every pagein/pageout. With THP,
  * it will be incremated by the number of pages. This counter is used for
@@ -4037,92 +4052,6 @@ static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
 }
 #endif
 
-
-/* For read statistics */
-enum {
-        MCS_CACHE,
-        MCS_RSS,
-        MCS_FILE_MAPPED,
-        MCS_SWAP,
-        MCS_PGPGIN,
-        MCS_PGPGOUT,
-        MCS_PGFAULT,
-        MCS_PGMAJFAULT,
-        MCS_INACTIVE_ANON,
-        MCS_ACTIVE_ANON,
-        MCS_INACTIVE_FILE,
-        MCS_ACTIVE_FILE,
-        MCS_UNEVICTABLE,
-        NR_MCS_STAT,
-};
-
-struct mcs_total_stat {
-        s64 stat[NR_MCS_STAT];
-};
-
-static const char *memcg_stat_strings[NR_MCS_STAT] = {
-        "cache",
-        "rss",
-        "mapped_file",
-        "swap",
-        "pgpgin",
-        "pgpgout",
-        "pgfault",
-        "pgmajfault",
-        "inactive_anon",
-        "active_anon",
-        "inactive_file",
-        "active_file",
-        "unevictable",
-};
-
-static void
-mem_cgroup_get_local_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s)
-{
-        s64 val;
-
-        /* per cpu stat */
-        val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_CACHE);
-        s->stat[MCS_CACHE] += val * PAGE_SIZE;
-        val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_RSS);
-        s->stat[MCS_RSS] += val * PAGE_SIZE;
-        val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED);
-        s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
-        val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGIN);
-        s->stat[MCS_PGPGIN] += val;
-        val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGOUT);
-        s->stat[MCS_PGPGOUT] += val;
-        if (do_swap_account) {
-                val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_SWAPOUT);
-                s->stat[MCS_SWAP] += val * PAGE_SIZE;
-        }
-        val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGFAULT);
-        s->stat[MCS_PGFAULT] += val;
-        val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGMAJFAULT);
-        s->stat[MCS_PGMAJFAULT] += val;
-
-        /* per zone stat */
-        val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_ANON));
-        s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
-        val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_ANON));
-        s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
-        val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_FILE));
-        s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
-        val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_FILE));
-        s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
-        val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE));
-        s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
-}
-
-static void
-mem_cgroup_get_total_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s)
-{
-        struct mem_cgroup *iter;
-
-        for_each_mem_cgroup_tree(iter, memcg)
-                mem_cgroup_get_local_stat(iter, s);
-}
-
 #ifdef CONFIG_NUMA
 static int mem_control_numa_stat_show(struct cgroup *cont, struct cftype *cft,
                                       struct seq_file *m)
@@ -4170,24 +4099,41 @@ static int mem_control_numa_stat_show(struct cgroup *cont, struct cftype *cft,
 }
 #endif /* CONFIG_NUMA */
 
+static const char * const mem_cgroup_lru_names[] = {
+        "inactive_anon",
+        "active_anon",
+        "inactive_file",
+        "active_file",
+        "unevictable",
+};
+
+static inline void mem_cgroup_lru_names_not_uptodate(void)
+{
+        BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
+}
+
 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
                                  struct seq_file *m)
 {
         struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
-        struct mcs_total_stat mystat;
-        int i;
-
-        memset(&mystat, 0, sizeof(mystat));
-        mem_cgroup_get_local_stat(memcg, &mystat);
-
+        struct mem_cgroup *mi;
+        unsigned int i;
 
-        for (i = 0; i < NR_MCS_STAT; i++) {
-                if (i == MCS_SWAP && !do_swap_account)
+        for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
+                if (i == MEM_CGROUP_STAT_SWAPOUT && !do_swap_account)
                         continue;
-                seq_printf(m, "%s %llu\n", memcg_stat_strings[i],
-                           (unsigned long long)mystat.stat[i]);
+                seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i],
+                           mem_cgroup_read_stat(memcg, i) * PAGE_SIZE);
         }
 
+        for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++)
+                seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i],
+                           mem_cgroup_read_events(memcg, i));
+
+        for (i = 0; i < NR_LRU_LISTS; i++)
+                seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i],
+                           mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE);
+
         /* Hierarchical information */
         {
                 unsigned long long limit, memsw_limit;
@@ -4198,13 +4144,31 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
                                    memsw_limit);
         }
 
-        memset(&mystat, 0, sizeof(mystat));
-        mem_cgroup_get_total_stat(memcg, &mystat);
-        for (i = 0; i < NR_MCS_STAT; i++) {
-                if (i == MCS_SWAP && !do_swap_account)
+        for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
+                long long val = 0;
+
+                if (i == MEM_CGROUP_STAT_SWAPOUT && !do_swap_account)
                         continue;
-                seq_printf(m, "total_%s %llu\n", memcg_stat_strings[i],
-                           (unsigned long long)mystat.stat[i]);
+                for_each_mem_cgroup_tree(mi, memcg)
+                        val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE;
+                seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val);
+        }
+
+        for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
+                unsigned long long val = 0;
+
+                for_each_mem_cgroup_tree(mi, memcg)
+                        val += mem_cgroup_read_events(mi, i);
+                seq_printf(m, "total_%s %llu\n",
+                           mem_cgroup_events_names[i], val);
+        }
+
+        for (i = 0; i < NR_LRU_LISTS; i++) {
+                unsigned long long val = 0;
+
+                for_each_mem_cgroup_tree(mi, memcg)
+                        val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE;
+                seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val);
         }
 
 #ifdef CONFIG_DEBUG_VM