[PATCH v2] mm/memcontrol:rewrite mem_cgroup_page_lruvec()

Hui Su
2020-11-08T15:26:42Z

mem_cgroup_page_lruvec() in memcontrol.c and
mem_cgroup_lruvec() in memcontrol.h is very similar
except for the param(page and memcg) which also can be
convert to each other.

So rewrite mem_cgroup_page_lruvec() with mem_cgroup_lruvec().

v1->v2:
use page_memcg() instead of 'page->mem_cgroup'.

Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Hui Su <sh_def@163.com>
---
include/linux/memcontrol.h | 16 +++++++++++++--
mm/memcontrol.c | 40 --------------------------------------
2 files changed, 14 insertions(+), 42 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index e391e3c56de5..727af7c74e91 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -457,9 +457,10 @@ mem_cgroup_nodeinfo(struct mem_cgroup *memcg, int nid)
/**
* mem_cgroup_lruvec - get the lru list vector for a memcg & node
* @memcg: memcg of the wanted lruvec
+ * @pgdat: pglist_data
*
* Returns the lru list vector holding pages for a given @memcg &
- * @node combination. This can be the node lruvec, if the memory
+ * @pgdat combination. This can be the node lruvec, if the memory
* controller is disabled.
*/
static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
@@ -489,7 +490,18 @@ static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
return lruvec;
}

-struct lruvec *mem_cgroup_page_lruvec(struct page *, struct pglist_data *);
+/**
+ * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
+ * @page: the page
+ * @pgdat: pgdat of the page
+ *
+ * This function relies on page->mem_cgroup being stable.
+ */
+static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
+ struct pglist_data *pgdat)
+{
+ return mem_cgroup_lruvec(page_memcg(page), pgdat);
+}

struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3dcbf24d2227..9d4e1150b194 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1330,46 +1330,6 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
return ret;
}

-/**
- * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
- * @page: the page
- * @pgdat: pgdat of the page
- *
- * This function relies on page->mem_cgroup being stable - see the
- * access rules in commit_charge().
- */
-struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct pglist_data *pgdat)
-{
- struct mem_cgroup_per_node *mz;
- struct mem_cgroup *memcg;
- struct lruvec *lruvec;
-
- if (mem_cgroup_disabled()) {
- lruvec = &pgdat->__lruvec;
- goto out;
- }
-
- memcg = page->mem_cgroup;
- /*
- * Swapcache readahead pages are added to the LRU - and
- * possibly migrated - before they are charged.
- */
- if (!memcg)
- memcg = root_mem_cgroup;
-
- mz = mem_cgroup_page_nodeinfo(memcg, page);
- lruvec = &mz->lruvec;
-out:
- /*
- * Since a node can be onlined after the mem_cgroup was created,
- * we have to be prepared to initialize lruvec->zone here;
- * and if offlined then reonlined, we need to reinitialize it.
- */
- if (unlikely(lruvec->pgdat != pgdat))
- lruvec->pgdat = pgdat;
- return lruvec;
-}
-
/**
* mem_cgroup_update_lru_size - account for adding or removing an lru page
* @lruvec: mem_cgroup per zone lru vector
--
2.29.0