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authorWei Yang <richard.weiyang@gmail.com>2022-04-28 23:15:59 -0700
committerakpm <akpm@linux-foundation.org>2022-04-28 23:15:59 -0700
commita9320aae68a1cd3f41b9846e24504b09ffc3311e (patch)
treeedde95609f76f436d12ab4e23b469789e83bb39f
parent89d8330ccf2ad4c0744e1d1b77ffe2deb1641e54 (diff)
mm/memcg: move generation assignment and comparison together
For each round-trip, we assign generation on first invocation and compare it on subsequent invocations. Let's move them together to make it more self-explaining. Also this reduce a check on prev. [hannes@cmpxchg.org: better comment to explain reclaim model] Link: https://lkml.kernel.org/r/20220330234719.18340-4-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--mm/memcontrol.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1b76d5698900..1ae0a2afe476 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1021,7 +1021,13 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
mz = root->nodeinfo[reclaim->pgdat->node_id];
iter = &mz->iter;
- if (prev && reclaim->generation != iter->generation)
+ /*
+ * On start, join the current reclaim iteration cycle.
+ * Exit when a concurrent walker completes it.
+ */
+ if (!prev)
+ reclaim->generation = iter->generation;
+ else if (reclaim->generation != iter->generation)
goto out_unlock;
while (1) {
@@ -1083,8 +1089,6 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
if (!memcg)
iter->generation++;
- else if (!prev)
- reclaim->generation = iter->generation;
}
out_unlock: