diff options
| author | Vladimir Davydov <vdavydov@parallels.com> | 2015-01-17 11:23:42 +1100 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2015-01-17 11:23:42 +1100 |
| commit | 25192a98c0a2fd18671e48fabed47a22de9d4371 (patch) | |
| tree | ef74d3455b582459f458ac4b7e3de66f38a11e9e /mm/vmscan.c | |
| parent | 56f3cf106f230fbcb35b09de757bf8cd3b0d3455 (diff) | |
vmscan: force scan offline memory cgroups
Since commit b2052564e66d ("mm: memcontrol: continue cache reclaim from
offlined groups") pages charged to a memory cgroup are not reparented when
the cgroup is removed. Instead, they are supposed to be reclaimed in a
regular way, along with pages accounted to online memory cgroups.
However, an lruvec of an offline memory cgroup will sooner or later get so
small that it will be scanned only at low scan priorities (see
get_scan_count()). Therefore, if there are enough reclaimable pages in
big lruvecs, pages accounted to offline memory cgroups will never be
scanned at all, wasting memory.
Fix this by unconditionally forcing scanning dead lruvecs from kswapd.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 1525d24811d8..b89097185f46 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1941,8 +1941,12 @@ static void get_scan_count(struct lruvec *lruvec, int swappiness, * latencies, so it's better to scan a minimum amount there as * well. */ - if (current_is_kswapd() && !zone_reclaimable(zone)) - force_scan = true; + if (current_is_kswapd()) { + if (!zone_reclaimable(zone)) + force_scan = true; + if (!mem_cgroup_lruvec_online(lruvec)) + force_scan = true; + } if (!global_reclaim(sc)) force_scan = true; |