mm: vmscan: do not scan anon pages if memcg swap limit is hit
We don't scan anonymous memory if we ran out of swap, neither should we do
it in case memcg swap limit is hit, because swap out is impossible anyway.
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@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 1ff552e..bcb3871 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5748,6 +5748,19 @@
rcu_read_unlock();
}
+long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
+{
+ long nr_swap_pages = get_nr_swap_pages();
+
+ if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
+ return nr_swap_pages;
+ for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg))
+ nr_swap_pages = min_t(long, nr_swap_pages,
+ READ_ONCE(memcg->swap.limit) -
+ page_counter_read(&memcg->swap));
+ return nr_swap_pages;
+}
+
/* for remember boot option*/
#ifdef CONFIG_MEMCG_SWAP_ENABLED
static int really_do_swap_account __initdata = 1;