+ mm-memcontrol-reparent-nr_deferred-when-memcg-offline.patch added to -mm tree

+ mm-memcontrol-reparent-nr_deferred-when-memcg-offline.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm: memcontrol: reparent nr_deferred when memcg offline
has been added to the -mm tree.  Its filename is
     mm-memcontrol-reparent-nr_deferred-when-memcg-offline.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-reparent-nr_deferred-when-memcg-offline.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-reparent-nr_deferred-when-memcg-offline.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Yang Shi <shy828301@gmail.com>
Subject: mm: memcontrol: reparent nr_deferred when memcg offline

Now shrinker's nr_deferred is per memcg for memcg aware shrinkers, add to
parent's corresponding nr_deferred when memcg offline.

Link: https://lkml.kernel.org/r/20210311190845.9708-13-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/memcontrol.h |    1 +
 mm/memcontrol.c            |    1 +
 mm/vmscan.c                |   24 ++++++++++++++++++++++++
 3 files changed, 26 insertions(+)

--- a/include/linux/memcontrol.h~mm-memcontrol-reparent-nr_deferred-when-memcg-offline
+++ a/include/linux/memcontrol.h
@@ -1537,6 +1537,7 @@ static inline bool mem_cgroup_under_sock
 int alloc_shrinker_info(struct mem_cgroup *memcg);
 void free_shrinker_info(struct mem_cgroup *memcg);
 void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id);
+void reparent_shrinker_deferred(struct mem_cgroup *memcg);
 #else
 #define mem_cgroup_sockets_enabled 0
 static inline void mem_cgroup_sk_alloc(struct sock *sk) { };
--- a/mm/memcontrol.c~mm-memcontrol-reparent-nr_deferred-when-memcg-offline
+++ a/mm/memcontrol.c
@@ -5167,6 +5167,7 @@ static void mem_cgroup_css_offline(struc
 	page_counter_set_low(&memcg->memory, 0);
 
 	memcg_offline_kmem(memcg);
+	reparent_shrinker_deferred(memcg);
 	wb_memcg_offline(memcg);
 
 	drain_all_stock(memcg);
--- a/mm/vmscan.c~mm-memcontrol-reparent-nr_deferred-when-memcg-offline
+++ a/mm/vmscan.c
@@ -397,6 +397,30 @@ static long add_nr_deferred_memcg(long n
 	return atomic_long_add_return(nr, &info->nr_deferred[shrinker->id]);
 }
 
+void reparent_shrinker_deferred(struct mem_cgroup *memcg)
+{
+	int i, nid;
+	long nr;
+	struct mem_cgroup *parent;
+	struct shrinker_info *child_info, *parent_info;
+
+	parent = parent_mem_cgroup(memcg);
+	if (!parent)
+		parent = root_mem_cgroup;
+
+	/* Prevent from concurrent shrinker_info expand */
+	down_read(&shrinker_rwsem);
+	for_each_node(nid) {
+		child_info = shrinker_info_protected(memcg, nid);
+		parent_info = shrinker_info_protected(parent, nid);
+		for (i = 0; i < shrinker_nr_max; i++) {
+			nr = atomic_long_read(&child_info->nr_deferred[i]);
+			atomic_long_add(nr, &parent_info->nr_deferred[i]);
+		}
+	}
+	up_read(&shrinker_rwsem);
+}
+
 static bool cgroup_reclaim(struct scan_control *sc)
 {
 	return sc->target_mem_cgroup;
_

Patches currently in -mm which might be from shy828301@gmail.com are

mm-vmscan-use-nid-from-shrink_control-for-tracepoint.patch
mm-vmscan-consolidate-shrinker_maps-handling-code.patch
mm-vmscan-use-shrinker_rwsem-to-protect-shrinker_maps-allocation.patch
mm-vmscan-remove-memcg_shrinker_map_size.patch
mm-vmscan-use-kvfree_rcu-instead-of-call_rcu.patch
mm-memcontrol-rename-shrinker_map-to-shrinker_info.patch
mm-vmscan-add-shrinker_info_protected-helper.patch
mm-vmscan-use-a-new-flag-to-indicate-shrinker-is-registered.patch
mm-vmscan-add-per-memcg-shrinker-nr_deferred.patch
mm-vmscan-use-per-memcg-nr_deferred-of-shrinker.patch
mm-vmscan-dont-need-allocate-shrinker-nr_deferred-for-memcg-aware-shrinkers.patch
mm-memcontrol-reparent-nr_deferred-when-memcg-offline.patch
mm-vmscan-shrink-deferred-objects-proportional-to-priority.patch