mm: memcg: print statistics directly to seq_file

Being able to use seq_printf() allows being smarter about statistics
name strings, which are currently listed twice, with the only difference
being a "total_" prefix on the hierarchical version.

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>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ba9e1b131b4d8e5388cde771a066dcc95b22fb15..4200f5c595795774f9004e8d8572747054482f23 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4060,26 +4060,22 @@ struct mcs_total_stat {
        s64 stat[NR_MCS_STAT];
 };
 
-static struct {
-       char *local_name;
-       char *total_name;
-} memcg_stat_strings[NR_MCS_STAT] = {
-       {"cache", "total_cache"},
-       {"rss", "total_rss"},
-       {"mapped_file", "total_mapped_file"},
-       {"pgpgin", "total_pgpgin"},
-       {"pgpgout", "total_pgpgout"},
-       {"swap", "total_swap"},
-       {"pgfault", "total_pgfault"},
-       {"pgmajfault", "total_pgmajfault"},
-       {"inactive_anon", "total_inactive_anon"},
-       {"active_anon", "total_active_anon"},
-       {"inactive_file", "total_inactive_file"},
-       {"active_file", "total_active_file"},
-       {"unevictable", "total_unevictable"}
+static const char *memcg_stat_strings[NR_MCS_STAT] = {
+       "cache",
+       "rss",
+       "mapped_file",
+       "pgpgin",
+       "pgpgout",
+       "swap",
+       "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)
 {
@@ -4175,7 +4171,7 @@ static int mem_control_numa_stat_show(struct cgroup *cont, struct cftype *cft,
 #endif /* CONFIG_NUMA */
 
 static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
-                                struct cgroup_map_cb *cb)
+                                struct seq_file *m)
 {
        struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
        struct mcs_total_stat mystat;
@@ -4188,16 +4184,18 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
        for (i = 0; i < NR_MCS_STAT; i++) {
                if (i == MCS_SWAP && !do_swap_account)
                        continue;
-               cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
+               seq_printf(m, "%s %llu\n", memcg_stat_strings[i],
+                          (unsigned long long)mystat.stat[i]);
        }
 
        /* Hierarchical information */
        {
                unsigned long long limit, memsw_limit;
                memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit);
-               cb->fill(cb, "hierarchical_memory_limit", limit);
+               seq_printf(m, "hierarchical_memory_limit %llu\n", limit);
                if (do_swap_account)
-                       cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
+                       seq_printf(m, "hierarchical_memsw_limit %llu\n",
+                                  memsw_limit);
        }
 
        memset(&mystat, 0, sizeof(mystat));
@@ -4205,7 +4203,8 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
        for (i = 0; i < NR_MCS_STAT; i++) {
                if (i == MCS_SWAP && !do_swap_account)
                        continue;
-               cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
+               seq_printf(m, "total_%s %llu\n", memcg_stat_strings[i],
+                          (unsigned long long)mystat.stat[i]);
        }
 
 #ifdef CONFIG_DEBUG_VM
@@ -4226,10 +4225,10 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
                                recent_scanned[0] += rstat->recent_scanned[0];
                                recent_scanned[1] += rstat->recent_scanned[1];
                        }
-               cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
-               cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
-               cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
-               cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
+               seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]);
+               seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]);
+               seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]);
+               seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]);
        }
 #endif
 
@@ -4663,7 +4662,7 @@ static struct cftype mem_cgroup_files[] = {
        },
        {
                .name = "stat",
-               .read_map = mem_control_stat_show,
+               .read_seq_string = mem_control_stat_show,
        },
        {
                .name = "force_empty",