[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20240905003058.1859929-6-kinseyho@google.com>
Date: Thu, 5 Sep 2024 00:30:54 +0000
From: Kinsey Ho <kinseyho@...gle.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-mm@...ck.org, linux-kernel@...r.kernel.org, cgroups@...r.kernel.org,
Yosry Ahmed <yosryahmed@...gle.com>, Roman Gushchin <roman.gushchin@...ux.dev>,
Johannes Weiner <hannes@...xchg.org>, Michal Hocko <mhocko@...nel.org>,
Shakeel Butt <shakeel.butt@...ux.dev>, Muchun Song <muchun.song@...ux.dev>,
Tejun Heo <tj@...nel.org>, Zefan Li <lizefan.x@...edance.com>, mkoutny@...e.com,
"T . J . Mercier" <tjmercier@...gle.com>, Hugh Dickins <hughd@...gle.com>, Kinsey Ho <kinseyho@...gle.com>
Subject: [PATCH mm-unstable v4 5/5] mm: clean up mem_cgroup_iter()
A clean up to make variable names more clear and to improve code
readability.
No functional change.
Signed-off-by: Kinsey Ho <kinseyho@...gle.com>
Reviewed-by: T.J. Mercier <tjmercier@...gle.com>
Cc: Johannes Weiner <hannes@...xchg.org>
Cc: Michal Hocko <mhocko@...nel.org>
Cc: Michal Koutný <mkoutny@...e.com>
Cc: Muchun Song <muchun.song@...ux.dev>
Cc: Roman Gushchin <roman.gushchin@...ux.dev>
Cc: Shakeel Butt <shakeel.butt@...ux.dev>
Cc: Tejun Heo <tj@...nel.org>
Cc: Yosry Ahmed <yosryahmed@...gle.com>
Cc: Zefan Li <lizefan.x@...edance.com>
Cc: Hugh Dickins <hughd@...gle.com>
---
mm/memcontrol.c | 32 ++++++++++++--------------------
1 file changed, 12 insertions(+), 20 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ce5d066393c9..31db8467f19d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -989,8 +989,8 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
{
struct mem_cgroup_reclaim_iter *iter;
struct cgroup_subsys_state *css;
- struct mem_cgroup *memcg;
- struct mem_cgroup *pos = NULL;
+ struct mem_cgroup *pos;
+ struct mem_cgroup *next;
if (mem_cgroup_disabled())
return NULL;
@@ -1000,14 +1000,13 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
rcu_read_lock();
restart:
- memcg = NULL;
+ next = NULL;
if (reclaim) {
int gen;
- struct mem_cgroup_per_node *mz;
+ int nid = reclaim->pgdat->node_id;
- mz = root->nodeinfo[reclaim->pgdat->node_id];
- iter = &mz->iter;
+ iter = &root->nodeinfo[nid]->iter;
gen = atomic_read(&iter->generation);
/*
@@ -1020,29 +1019,22 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
goto out_unlock;
pos = READ_ONCE(iter->position);
- } else if (prev) {
+ } else
pos = prev;
- }
css = pos ? &pos->css : NULL;
- for (;;) {
- css = css_next_descendant_pre(css, &root->css);
- if (!css) {
- break;
- }
-
+ while ((css = css_next_descendant_pre(css, &root->css))) {
/*
* Verify the css and acquire a reference. The root
* is provided by the caller, so we know it's alive
* and kicking, and don't take an extra reference.
*/
- if (css == &root->css || css_tryget(css)) {
+ if (css == &root->css || css_tryget(css))
break;
- }
}
- memcg = mem_cgroup_from_css(css);
+ next = mem_cgroup_from_css(css);
if (reclaim) {
/*
@@ -1050,13 +1042,13 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
* thread, so check that the value hasn't changed since we read
* it to avoid reclaiming from the same cgroup twice.
*/
- if (cmpxchg(&iter->position, pos, memcg) != pos) {
+ if (cmpxchg(&iter->position, pos, next) != pos) {
if (css && css != &root->css)
css_put(css);
goto restart;
}
- if (!memcg) {
+ if (!next) {
atomic_inc(&iter->generation);
/*
@@ -1075,7 +1067,7 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
if (prev && prev != root)
css_put(&prev->css);
- return memcg;
+ return next;
}
/**
--
2.46.0.469.g59c65b2a67-goog
Powered by blists - more mailing lists