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No functional change. Signed-off-by: Kinsey Ho --- mm/memcontrol.c | 36 ++++++++++++++---------------------- 1 file changed, 14 insertions(+), 22 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 4314a2b8848d..7e3e95c62122 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -992,9 +992,9 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, struct mem_cgroup_reclaim_cookie *reclaim) { struct mem_cgroup_reclaim_iter *iter; - struct cgroup_subsys_state *css = NULL; - struct mem_cgroup *memcg = NULL; - struct mem_cgroup *pos = NULL; + struct cgroup_subsys_state *css; + struct mem_cgroup *pos; + struct mem_cgroup *next = NULL; if (mem_cgroup_disabled()) return NULL; @@ -1006,10 +1006,9 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, restart: 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); /* @@ -1022,43 +1021,36 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, goto out_unlock; pos = rcu_dereference(iter->position); - } else if (prev) { + } else pos = prev; - } - if (pos) - css = &pos->css; - - for (;;) { - css = css_next_descendant_pre(css, &root->css); - if (!css) { - break; - } + css = pos ? &pos->css : NULL; + 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)) { - memcg = mem_cgroup_from_css(css); + if (css == &root->css || css_tryget(css)) break; - } } + next = mem_cgroup_from_css(css); + if (reclaim) { /* * The position could have already been updated by a competing * 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); /* @@ -1077,7 +1069,7 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, if (prev && prev != root) css_put(&prev->css); - return memcg; + return next; } /** -- 2.45.2.1089.g2a221341d9-goog