[PATCH 13/13] mm: enlarge the int parameter of update_lru_size()

From: Yu Zhao
Date: Thu Sep 17 2020 - 23:01:31 EST


In update_lru_sizes(), we call update_lru_size() with a long
argument, whereas the callee only takes an int parameter. Though this
isn't causing any overflow I'm aware of, it's not a good idea to
go through the truncation since the underlying counters are already
in long.

This patch enlarges all relevant parameters on the path to the final
underlying counters:
update_lru_size(int -> long)
if memcg:
__mod_lruvec_state(int -> long)
if smp:
__mod_node_page_state(long)
else:
__mod_node_page_state(int -> long)
__mod_memcg_lruvec_state(int -> long)
__mod_memcg_state(int -> long)
else:
__mod_lruvec_state(int -> long)
if smp:
__mod_node_page_state(long)
else:
__mod_node_page_state(int -> long)

__mod_zone_page_state(long)

if memcg:
mem_cgroup_update_lru_size(int -> long)

Note that __mod_node_page_state() for the smp case and
__mod_zone_page_state() already use long. So this change also fixes
the inconsistency.

Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
---
include/linux/memcontrol.h | 14 +++++++-------
include/linux/mm_inline.h | 2 +-
include/linux/vmstat.h | 2 +-
mm/memcontrol.c | 10 +++++-----
4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index d0b036123c6a..fcd1829f8382 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -621,7 +621,7 @@ static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);

void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
- int zid, int nr_pages);
+ int zid, long nr_pages);

static inline
unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
@@ -707,7 +707,7 @@ static inline unsigned long memcg_page_state_local(struct mem_cgroup *memcg,
return x;
}

-void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val);
+void __mod_memcg_state(struct mem_cgroup *memcg, int idx, long val);

/* idx can be of type enum memcg_stat_item or node_stat_item */
static inline void mod_memcg_state(struct mem_cgroup *memcg,
@@ -790,9 +790,9 @@ static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
}

void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
- int val);
+ long val);
void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
- int val);
+ long val);
void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val);

void mod_memcg_obj_state(void *p, int idx, int val);
@@ -1166,7 +1166,7 @@ static inline unsigned long memcg_page_state_local(struct mem_cgroup *memcg,

static inline void __mod_memcg_state(struct mem_cgroup *memcg,
int idx,
- int nr)
+ long nr)
{
}

@@ -1201,12 +1201,12 @@ static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
}

static inline void __mod_memcg_lruvec_state(struct lruvec *lruvec,
- enum node_stat_item idx, int val)
+ enum node_stat_item idx, long val)
{
}

static inline void __mod_lruvec_state(struct lruvec *lruvec,
- enum node_stat_item idx, int val)
+ enum node_stat_item idx, long val)
{
__mod_node_page_state(lruvec_pgdat(lruvec), idx, val);
}
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 355ea1ee32bd..18e85071b44a 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -26,7 +26,7 @@ static inline int page_is_file_lru(struct page *page)

static __always_inline void update_lru_size(struct lruvec *lruvec,
enum lru_list lru, enum zone_type zid,
- int nr_pages)
+ long nr_pages)
{
struct pglist_data *pgdat = lruvec_pgdat(lruvec);

diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 91220ace31da..2ae35e8c45f0 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -310,7 +310,7 @@ static inline void __mod_zone_page_state(struct zone *zone,
}

static inline void __mod_node_page_state(struct pglist_data *pgdat,
- enum node_stat_item item, int delta)
+ enum node_stat_item item, long delta)
{
node_page_state_add(delta, pgdat, item);
}
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index cfa6cbad21d5..11bc4bb36882 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -774,7 +774,7 @@ mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz)
* @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item
* @val: delta to add to the counter, can be negative
*/
-void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val)
+void __mod_memcg_state(struct mem_cgroup *memcg, int idx, long val)
{
long x, threshold = MEMCG_CHARGE_BATCH;

@@ -812,7 +812,7 @@ parent_nodeinfo(struct mem_cgroup_per_node *pn, int nid)
}

void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
- int val)
+ long val)
{
struct mem_cgroup_per_node *pn;
struct mem_cgroup *memcg;
@@ -853,7 +853,7 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
* change of state at this level: per-node, per-cgroup, per-lruvec.
*/
void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
- int val)
+ long val)
{
/* Update node */
__mod_node_page_state(lruvec_pgdat(lruvec), idx, val);
@@ -1354,7 +1354,7 @@ struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct pglist_data *pgd
* so as to allow it to check that lru_size 0 is consistent with list_empty).
*/
void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
- int zid, int nr_pages)
+ int zid, long nr_pages)
{
struct mem_cgroup_per_node *mz;
unsigned long *lru_size;
@@ -1371,7 +1371,7 @@ void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,

size = *lru_size;
if (WARN_ONCE(size < 0,
- "%s(%p, %d, %d): lru_size %ld\n",
+ "%s(%p, %d, %ld): lru_size %ld\n",
__func__, lruvec, lru, nr_pages, size)) {
VM_BUG_ON(1);
*lru_size = 0;
--
2.28.0.681.g6f77f65b4e-goog