[BUGFIX][PATCH mmotm] memcg fix calclation of active_ratio (resend)

From: KAMEZAWA Hiroyuki
Date: Fri Dec 12 2008 - 03:33:17 EST


Resend a patch from kosaki. I confirmed this works well.

==
From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Currently, inactive_ratio of memcg is calculated at setting limit.
because page_alloc.c does so and current implementation is straightforward porting.

However, memcg introduced hierarchy feature recently.
In hierarchy restriction, memory limit is not only decided memory.limit_in_bytes of current cgroup,
but also parent limit and sibling memory usage.

Then, The optimal inactive_ratio is changed frequently.
So, everytime calculation is better.

Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
CC: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 3 --
mm/memcontrol.c | 64 +++++++++++++++++++++------------------------
mm/vmscan.c | 2 -
3 files changed, 33 insertions(+), 36 deletions(-)

Index: b/include/linux/memcontrol.h
===================================================================
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -95,8 +95,7 @@ extern void mem_cgroup_note_reclaim_prio
int priority);
extern void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem,
int priority);
-int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg,
- struct zone *zone);
+int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg);
unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
struct zone *zone,
enum lru_list lru);
Index: b/mm/memcontrol.c
===================================================================
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -167,9 +167,6 @@ struct mem_cgroup {

unsigned int swappiness;

-
- unsigned int inactive_ratio;
-
/*
* statistics. This must be placed at the end of memcg.
*/
@@ -433,15 +430,43 @@ void mem_cgroup_record_reclaim_priority(
spin_unlock(&mem->reclaim_param_lock);
}

-int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone)
+static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
{
unsigned long active;
unsigned long inactive;
+ unsigned long gb;
+ unsigned long inactive_ratio;

inactive = mem_cgroup_get_all_zonestat(memcg, LRU_INACTIVE_ANON);
active = mem_cgroup_get_all_zonestat(memcg, LRU_ACTIVE_ANON);

- if (inactive * memcg->inactive_ratio < active)
+ gb = (inactive + active) >> (30 - PAGE_SHIFT);
+ if (gb)
+ inactive_ratio = int_sqrt(10 * gb);
+ else
+ inactive_ratio = 1;
+
+ if (present_pages) {
+ present_pages[0] = inactive;
+ present_pages[1] = active;
+ }
+
+ return inactive_ratio;
+}
+
+int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
+{
+ unsigned long active;
+ unsigned long inactive;
+ unsigned long present_pages[2];
+ unsigned long inactive_ratio;
+
+ inactive_ratio = calc_inactive_ratio(memcg, present_pages);
+
+ inactive = present_pages[0];
+ active = present_pages[1];
+
+ if (inactive * inactive_ratio < active)
return 1;

return 0;
@@ -1410,29 +1435,6 @@ int mem_cgroup_shrink_usage(struct mm_st
return 0;
}

-/*
- * The inactive anon list should be small enough that the VM never has to
- * do too much work, but large enough that each inactive page has a chance
- * to be referenced again before it is swapped out.
- *
- * this calculation is straightforward porting from
- * page_alloc.c::setup_per_zone_inactive_ratio().
- * it describe more detail.
- */
-static void mem_cgroup_set_inactive_ratio(struct mem_cgroup *memcg)
-{
- unsigned int gb, ratio;
-
- gb = res_counter_read_u64(&memcg->res, RES_LIMIT) >> 30;
- if (gb)
- ratio = int_sqrt(10 * gb);
- else
- ratio = 1;
-
- memcg->inactive_ratio = ratio;
-
-}
-
static DEFINE_MUTEX(set_limit_mutex);

static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
@@ -1472,9 +1474,6 @@ static int mem_cgroup_resize_limit(struc
if (!progress) retry_count--;
}

- if (!ret)
- mem_cgroup_set_inactive_ratio(memcg);
-
return ret;
}

@@ -1833,7 +1832,7 @@ static int mem_control_stat_show(struct
}

#ifdef CONFIG_DEBUG_VM
- cb->fill(cb, "inactive_ratio", mem_cont->inactive_ratio);
+ cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));

{
int nid, zid;
@@ -2125,7 +2124,6 @@ mem_cgroup_create(struct cgroup_subsys *
res_counter_init(&mem->res, NULL);
res_counter_init(&mem->memsw, NULL);
}
- mem_cgroup_set_inactive_ratio(mem);
mem->last_scanned_child = NULL;
spin_lock_init(&mem->reclaim_param_lock);

Index: b/mm/vmscan.c
===================================================================
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1394,7 +1394,7 @@ static int inactive_anon_is_low(struct z
if (scanning_global_lru(sc))
low = inactive_anon_is_low_global(zone);
else
- low = mem_cgroup_inactive_anon_is_low(sc->mem_cgroup, zone);
+ low = mem_cgroup_inactive_anon_is_low(sc->mem_cgroup);
return low;
}



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