The patch titled
Subject: mm/memcg: optimize memory.numa_stat like memory.stat
has been added to the -mm tree. Its filename is
memcg-optimize-memorynuma_stat-like-memorystat.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/memcg-optimize-memorynuma_stat-like-memorystat.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/memcg-optimize-memorynuma_stat-like-memorystat.patch
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------------------------------------------------------
From: Shakeel Butt <shakeelb@xxxxxxxxxx>
Subject: mm/memcg: optimize memory.numa_stat like memory.stat
Currently reading memory.numa_stat traverses the underlying memcg tree
multiple times to accumulate the stats to present the hierarchical view of
the memcg tree. However the kernel already maintains the hierarchical
view of the stats and use it in memory.stat. Just use the same mechanism
in memory.numa_stat as well.
I ran a simple benchmark which reads root_mem_cgroup's memory.numa_stat
file in the presense of 10000 memcgs. The results are:
Without the patch:
$ time cat /dev/cgroup/memory/memory.numa_stat > /dev/null
real 0m0.700s
user 0m0.001s
sys 0m0.697s
With the patch:
$ time cat /dev/cgroup/memory/memory.numa_stat > /dev/null
real 0m0.001s
user 0m0.001s
sys 0m0.000s
Link: http://lkml.kernel.org/r/20200304022058.248270-1-shakeelb@xxxxxxxxxx
Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 50 +++++++++++++++++++++++-----------------------
1 file changed, 26 insertions(+), 24 deletions(-)
--- a/mm/memcontrol.c~memcg-optimize-memorynuma_stat-like-memorystat
+++ a/mm/memcontrol.c
@@ -3653,32 +3653,40 @@ static int mem_cgroup_move_charge_write(
#define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
- int nid, unsigned int lru_mask)
+ int nid, unsigned int lru_mask, bool tree)
{
struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid));
unsigned long nr = 0;
enum lru_list lru;
+ unsigned long (*page_state)(struct lruvec *lruvec,
+ enum node_stat_item idx);
VM_BUG_ON((unsigned)nid >= nr_node_ids);
+ page_state = tree ? lruvec_page_state : lruvec_page_state_local;
+
for_each_lru(lru) {
if (!(BIT(lru) & lru_mask))
continue;
- nr += lruvec_page_state_local(lruvec, NR_LRU_BASE + lru);
+ nr += page_state(lruvec, NR_LRU_BASE + lru);
}
return nr;
}
static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
- unsigned int lru_mask)
+ unsigned int lru_mask,
+ bool tree)
{
unsigned long nr = 0;
enum lru_list lru;
+ unsigned long (*page_state)(struct mem_cgroup *memcg, int idx);
+
+ page_state = tree ? memcg_page_state : memcg_page_state_local;
for_each_lru(lru) {
if (!(BIT(lru) & lru_mask))
continue;
- nr += memcg_page_state_local(memcg, NR_LRU_BASE + lru);
+ nr += page_state(memcg, NR_LRU_BASE + lru);
}
return nr;
}
@@ -3698,34 +3706,28 @@ static int memcg_numa_stat_show(struct s
};
const struct numa_stat *stat;
int nid;
- unsigned long nr;
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
- nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask);
- seq_printf(m, "%s=%lu", stat->name, nr);
- for_each_node_state(nid, N_MEMORY) {
- nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
- stat->lru_mask);
- seq_printf(m, " N%d=%lu", nid, nr);
- }
+ seq_printf(m, "%s=%lu", stat->name,
+ mem_cgroup_nr_lru_pages(memcg, stat->lru_mask,
+ false));
+ for_each_node_state(nid, N_MEMORY)
+ seq_printf(m, " N%d=%lu", nid,
+ mem_cgroup_node_nr_lru_pages(memcg, nid,
+ stat->lru_mask, false));
seq_putc(m, '\n');
}
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
- struct mem_cgroup *iter;
- nr = 0;
- for_each_mem_cgroup_tree(iter, memcg)
- nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask);
- seq_printf(m, "hierarchical_%s=%lu", stat->name, nr);
- for_each_node_state(nid, N_MEMORY) {
- nr = 0;
- for_each_mem_cgroup_tree(iter, memcg)
- nr += mem_cgroup_node_nr_lru_pages(
- iter, nid, stat->lru_mask);
- seq_printf(m, " N%d=%lu", nid, nr);
- }
+ seq_printf(m, "hierarchical_%s=%lu", stat->name,
+ mem_cgroup_nr_lru_pages(memcg, stat->lru_mask,
+ true));
+ for_each_node_state(nid, N_MEMORY)
+ seq_printf(m, " N%d=%lu", nid,
+ mem_cgroup_node_nr_lru_pages(memcg, nid,
+ stat->lru_mask, true));
seq_putc(m, '\n');
}
_
Patches currently in -mm which might be from shakeelb@xxxxxxxxxx are
memcg-css_tryget_online-cleanups.patch
memcg-optimize-memorynuma_stat-like-memorystat.patch
