summaryrefslogtreecommitdiff
path: root/mm/memcontrol.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/memcontrol.c')
-rw-r--r--mm/memcontrol.c24
1 files changed, 5 insertions, 19 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 929162c5f45f..7474aa8e4026 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3710,27 +3710,13 @@ static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
if (mem_cgroup_is_root(memcg)) {
/*
- * We can reach here from irq context through:
- * uncharge_batch()
- * |--memcg_check_events()
- * |--mem_cgroup_threshold()
- * |--__mem_cgroup_threshold()
- * |--mem_cgroup_usage
- *
- * rstat flushing is an expensive operation that should not be
- * done from irq context; use stale stats in this case.
- * Arguably, usage threshold events are not reliable on the root
- * memcg anyway since its usage is ill-defined.
- *
- * Additionally, other call paths through memcg_check_events()
- * disable irqs, so make sure we are flushing stats atomically.
+ * Approximate root's usage from global state. This isn't
+ * perfect, but the root usage was always an approximation.
*/
- if (in_task())
- mem_cgroup_flush_stats_atomic();
- val = memcg_page_state(memcg, NR_FILE_PAGES) +
- memcg_page_state(memcg, NR_ANON_MAPPED);
+ val = global_node_page_state(NR_FILE_PAGES) +
+ global_node_page_state(NR_ANON_MAPPED);
if (swap)
- val += memcg_page_state(memcg, MEMCG_SWAP);
+ val += total_swap_pages - get_nr_swap_pages();
} else {
if (!swap)
val = page_counter_read(&memcg->memory);