From: Sha Zhengju <handai.szj@xxxxxxxxxx>
Change the first argument of mem_cgroup_{update,inc,dec}_page_stat() from
'struct page *' to 'struct mem_cgroup *', and so move PageCgroupUsed(pc)
checking out of mem_cgroup_update_page_stat(). This is a prepare patch for
the following memcg page stat lock simplifying.
Signed-off-by: Sha Zhengju <handai.szj@xxxxxxxxxx>
---
include/linux/memcontrol.h | 14 +++++++-------
mm/memcontrol.c | 9 ++-------
mm/rmap.c | 28 +++++++++++++++++++++++++---
3 files changed, 34 insertions(+), 17 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index d6183f0..7af3ed3 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -163,20 +163,20 @@ static inline void mem_cgroup_end_update_page_stat(struct page *page,
rcu_read_unlock();
}
-void mem_cgroup_update_page_stat(struct page *page,
+void mem_cgroup_update_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_page_stat_item idx,
int val);
-static inline void mem_cgroup_inc_page_stat(struct page *page,
+static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_page_stat_item idx)
{
- mem_cgroup_update_page_stat(page, idx, 1);
+ mem_cgroup_update_page_stat(memcg, idx, 1);
}
-static inline void mem_cgroup_dec_page_stat(struct page *page,
+static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_page_stat_item idx)
{
- mem_cgroup_update_page_stat(page, idx, -1);
+ mem_cgroup_update_page_stat(memcg, idx, -1);
}
unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
@@ -347,12 +347,12 @@ static inline void mem_cgroup_end_update_page_stat(struct page *page,
{
}
-static inline void mem_cgroup_inc_page_stat(struct page *page,
+static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_page_stat_item idx)
{
}
-static inline void mem_cgroup_dec_page_stat(struct page *page,
+static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_page_stat_item idx)
{
}
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b31513e..a394ba4 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2367,18 +2367,13 @@ void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags)
move_unlock_mem_cgroup(pc->mem_cgroup, flags);
}
-void mem_cgroup_update_page_stat(struct page *page,
+void mem_cgroup_update_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_page_stat_item idx, int val)
{
- struct mem_cgroup *memcg;
- struct page_cgroup *pc = lookup_page_cgroup(page);
- unsigned long uninitialized_var(flags);
-
if (mem_cgroup_disabled())
return;
- memcg = pc->mem_cgroup;
- if (unlikely(!memcg || !PageCgroupUsed(pc)))
+ if (unlikely(!memcg))
return;
switch (idx) {
diff --git a/mm/rmap.c b/mm/rmap.c
index 6280da8..a03c2a9 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1109,12 +1109,24 @@ void page_add_file_rmap(struct page *page)
{
bool locked;
unsigned long flags;
+ struct page_cgroup *pc;
+ struct mem_cgroup *memcg = NULL;
mem_cgroup_begin_update_page_stat(page, &locked, &flags);
+ pc = lookup_page_cgroup(page);
+
+ rcu_read_lock();
+ memcg = pc->mem_cgroup;
+ if (unlikely(!PageCgroupUsed(pc)))
+ memcg = NULL;
+
if (atomic_inc_and_test(&page->_mapcount)) {
__inc_zone_page_state(page, NR_FILE_MAPPED);
- mem_cgroup_inc_page_stat(page, MEMCG_NR_FILE_MAPPED);
+ if (memcg)
+ mem_cgroup_inc_page_stat(memcg, MEMCG_NR_FILE_MAPPED);
}
+ rcu_read_unlock();
+
mem_cgroup_end_update_page_stat(page, &locked, &flags);
}
@@ -1129,14 +1141,22 @@ void page_remove_rmap(struct page *page)
bool anon = PageAnon(page);
bool locked;
unsigned long flags;
+ struct page_cgroup *pc;
+ struct mem_cgroup *memcg = NULL;
/*
* The anon case has no mem_cgroup page_stat to update; but may
* uncharge_page() below, where the lock ordering can deadlock if
* we hold the lock against page_stat move: so avoid it on anon.
*/
- if (!anon)
+ if (!anon) {
mem_cgroup_begin_update_page_stat(page, &locked, &flags);
+ pc = lookup_page_cgroup(page);
+ rcu_read_lock();
+ memcg = pc->mem_cgroup;
+ if (unlikely(!PageCgroupUsed(pc)))
+ memcg = NULL;
+ }
/* page still mapped by someone else? */
if (!atomic_add_negative(-1, &page->_mapcount))
@@ -1157,7 +1177,9 @@ void page_remove_rmap(struct page *page)
NR_ANON_TRANSPARENT_HUGEPAGES);
} else {
__dec_zone_page_state(page, NR_FILE_MAPPED);
- mem_cgroup_dec_page_stat(page, MEMCG_NR_FILE_MAPPED);
+ if (memcg)
+ mem_cgroup_dec_page_stat(memcg, MEMCG_NR_FILE_MAPPED);
+ rcu_read_unlock();
mem_cgroup_end_update_page_stat(page, &locked, &flags);
}
if (unlikely(PageMlocked(page)))
--
1.7.9.5
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