memcg: export memory cgroup's swappiness with mem_cgroup_swappiness()
Each memory cgroup has a 'swappiness' value which can be accessed by
get_swappiness(memcg). The major user is try_to_free_mem_cgroup_pages()
and swappiness is passed by argument. It's propagated by scan_control.
get_swappiness() is a static function but some planned updates will need
to get swappiness from files other than memcontrol.c This patch exports
get_swappiness() as mem_cgroup_swappiness(). With this, we can remove the
argument of swapiness from try_to_free... and drop swappiness from
scan_control. only memcg uses it.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ying Han <yinghan@google.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
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 e013b8e..506d116 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -249,7 +249,7 @@
atomic_t oom_lock;
atomic_t refcnt;
- unsigned int swappiness;
+ int swappiness;
/* OOM-Killer disable */
int oom_kill_disable;
@@ -1329,7 +1329,7 @@
return margin >> PAGE_SHIFT;
}
-static unsigned int get_swappiness(struct mem_cgroup *memcg)
+int mem_cgroup_swappiness(struct mem_cgroup *memcg)
{
struct cgroup *cgrp = memcg->css.cgroup;
@@ -1776,12 +1776,11 @@
/* we use swappiness of local cgroup */
if (check_soft) {
ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
- noswap, get_swappiness(victim), zone,
- &nr_scanned);
+ noswap, zone, &nr_scanned);
*total_scanned += nr_scanned;
} else
ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
- noswap, get_swappiness(victim));
+ noswap);
css_put(&victim->css);
/*
* At shrinking usage, we can't check we should stop here or
@@ -3826,7 +3825,7 @@
goto out;
}
progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
- false, get_swappiness(mem));
+ false);
if (!progress) {
nr_retries--;
/* maybe some writeback is necessary */
@@ -4288,7 +4287,7 @@
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
- return get_swappiness(memcg);
+ return mem_cgroup_swappiness(memcg);
}
static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
@@ -4997,7 +4996,7 @@
INIT_LIST_HEAD(&mem->oom_notify);
if (parent)
- mem->swappiness = get_swappiness(parent);
+ mem->swappiness = mem_cgroup_swappiness(parent);
atomic_set(&mem->refcnt, 1);
mem->move_charge_at_immigrate = 0;
mutex_init(&mem->thresholds_lock);