The patch titled
Subject: memcg: schedule high reclaim for remote memcgs on high_work
has been added to the -mm tree. Its filename is
memcg-schedule-high-reclaim-for-remote-memcgs-on-high_work.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/memcg-schedule-high-reclaim-for-remote-memcgs-on-high_work.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/memcg-schedule-high-reclaim-for-remote-memcgs-on-high_work.patch
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------------------------------------------------------
From: Shakeel Butt <shakeelb@xxxxxxxxxx>
Subject: memcg: schedule high reclaim for remote memcgs on high_work
If a memcg is over high limit, memory reclaim is scheduled to run on
return-to-userland. However it is assumed that the memcg is the current
process's memcg. With remote memcg charging for kmem or swapping in a
page charged to remote memcg, current process can trigger reclaim on
remote memcg. So, scheduling reclaim on return-to-userland for remote
memcgs will ignore the high reclaim altogether. So, punt the high reclaim
of remote memcgs to high_work.
Link: http://lkml.kernel.org/r/20190103015638.205424-1-shakeelb@xxxxxxxxxx
Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
--- a/mm/memcontrol.c~memcg-schedule-high-reclaim-for-remote-memcgs-on-high_work
+++ a/mm/memcontrol.c
@@ -2318,19 +2318,23 @@ done_restock:
* reclaim on returning to userland. We can perform reclaim here
* if __GFP_RECLAIM but let's always punt for simplicity and so that
* GFP_KERNEL can consistently be used during reclaim. @memcg is
- * not recorded as it most likely matches current's and won't
- * change in the meantime. As high limit is checked again before
- * reclaim, the cost of mismatch is negligible.
+ * not recorded as the return-to-userland high reclaim will only reclaim
+ * from current's memcg (or its ancestor). For other memcgs we punt them
+ * to work queue.
*/
do {
if (page_counter_read(&memcg->memory) > memcg->high) {
- /* Don't bother a random interrupted task */
- if (in_interrupt()) {
+ /*
+ * Don't bother a random interrupted task or if the
+ * memcg is not current's memcg's ancestor.
+ */
+ if (in_interrupt() ||
+ !mm_match_cgroup(current->mm, memcg)) {
schedule_work(&memcg->high_work);
- break;
+ } else {
+ current->memcg_nr_pages_over_high += batch;
+ set_notify_resume(current);
}
- current->memcg_nr_pages_over_high += batch;
- set_notify_resume(current);
break;
}
} while ((memcg = parent_mem_cgroup(memcg)));
_
Patches currently in -mm which might be from shakeelb@xxxxxxxxxx are
fork-memcg-fix-cached_stacks-case.patch
memcg-localize-memcg_kmem_enabled-check.patch
memcg-schedule-high-reclaim-for-remote-memcgs-on-high_work.patch
