[PATCH -mm v3 6/9] list_lru: get rid of ->active_nodes

From: Vladimir Davydov
Date: Thu Jan 08 2015 - 05:54:47 EST


The active_nodes mask allows us to skip empty nodes when walking over
list_lru items from all nodes in list_lru_count/walk. However, these
functions are never called from hot paths, so it doesn't seem we need
such kind of optimization there. OTOH, removing the mask will make it
easier to make list_lru per-memcg.

Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
---
include/linux/list_lru.h | 5 ++---
mm/list_lru.c | 10 +++-------
2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index f500a2e39b13..53c1d6b78270 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -31,7 +31,6 @@ struct list_lru_node {

struct list_lru {
struct list_lru_node *node;
- nodemask_t active_nodes;
};

void list_lru_destroy(struct list_lru *lru);
@@ -94,7 +93,7 @@ static inline unsigned long list_lru_count(struct list_lru *lru)
long count = 0;
int nid;

- for_each_node_mask(nid, lru->active_nodes)
+ for_each_node_state(nid, N_NORMAL_MEMORY)
count += list_lru_count_node(lru, nid);

return count;
@@ -142,7 +141,7 @@ list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
long isolated = 0;
int nid;

- for_each_node_mask(nid, lru->active_nodes) {
+ for_each_node_state(nid, N_NORMAL_MEMORY) {
isolated += list_lru_walk_node(lru, nid, isolate,
cb_arg, &nr_to_walk);
if (nr_to_walk <= 0)
diff --git a/mm/list_lru.c b/mm/list_lru.c
index f1a0db194173..07e198c77888 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -19,8 +19,7 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item)
WARN_ON_ONCE(nlru->nr_items < 0);
if (list_empty(item)) {
list_add_tail(item, &nlru->list);
- if (nlru->nr_items++ == 0)
- node_set(nid, lru->active_nodes);
+ nlru->nr_items++;
spin_unlock(&nlru->lock);
return true;
}
@@ -37,8 +36,7 @@ bool list_lru_del(struct list_lru *lru, struct list_head *item)
spin_lock(&nlru->lock);
if (!list_empty(item)) {
list_del_init(item);
- if (--nlru->nr_items == 0)
- node_clear(nid, lru->active_nodes);
+ nlru->nr_items--;
WARN_ON_ONCE(nlru->nr_items < 0);
spin_unlock(&nlru->lock);
return true;
@@ -90,8 +88,7 @@ restart:
case LRU_REMOVED_RETRY:
assert_spin_locked(&nlru->lock);
case LRU_REMOVED:
- if (--nlru->nr_items == 0)
- node_clear(nid, lru->active_nodes);
+ nlru->nr_items--;
WARN_ON_ONCE(nlru->nr_items < 0);
isolated++;
/*
@@ -133,7 +130,6 @@ int list_lru_init_key(struct list_lru *lru, struct lock_class_key *key)
if (!lru->node)
return -ENOMEM;

- nodes_clear(lru->active_nodes);
for (i = 0; i < nr_node_ids; i++) {
spin_lock_init(&lru->node[i].lock);
if (key)
--
1.7.10.4

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