+ mm-memcg-set-pos-to-prev-unconditionally.patch added to -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/memcg: set pos to prev unconditionally
has been added to the -mm tree.  Its filename is
     mm-memcg-set-pos-to-prev-unconditionally.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-memcg-set-pos-to-prev-unconditionally.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcg-set-pos-to-prev-unconditionally.patch

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------------------------------------------------------
From: Wei Yang <richard.weiyang@gmail.com>
Subject: mm/memcg: set pos to prev unconditionally

Current code sets pos to prev based on condition (prev && !reclaim), while
we can do this unconditionally.

Since:

  * If !reclaim, pos is the same as prev no matter it is NULL or not.
  * If reclaim, pos would be set properly from iter->position.

Link: https://lkml.kernel.org/r/20220225003437.12620-3-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memcontrol.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

--- a/mm/memcontrol.c~mm-memcg-set-pos-to-prev-unconditionally
+++ a/mm/memcontrol.c
@@ -1029,7 +1029,7 @@ struct mem_cgroup *mem_cgroup_iter(struc
 	struct mem_cgroup_reclaim_iter *iter;
 	struct cgroup_subsys_state *css = NULL;
 	struct mem_cgroup *memcg = NULL;
-	struct mem_cgroup *pos = NULL;
+	struct mem_cgroup *pos = prev;
 
 	if (mem_cgroup_disabled())
 		return NULL;
@@ -1037,9 +1037,6 @@ struct mem_cgroup *mem_cgroup_iter(struc
 	if (!root)
 		root = root_mem_cgroup;
 
-	if (prev && !reclaim)
-		pos = prev;
-
 	rcu_read_lock();
 
 	if (reclaim) {
_

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

mm-memcg-mem_cgroup_per_node-is-already-set-to-0-on-allocation.patch
mm-memcg-retrieve-parent-memcg-from-cssparent.patch
mm-memcg-set-memcg-after-css-verified-and-got-reference.patch
mm-memcg-set-pos-to-prev-unconditionally.patch
mm-memcg-move-generation-assignment-and-comparison-together.patch
mm-page_alloc-add-same-penalty-is-enough-to-get-round-robin-order.patch
mm-page_alloc-add-penalty-to-local_node.patch
memcg-do-not-tweak-node-in-alloc_mem_cgroup_per_node_info.patch