mm/list_lru.c: add memcg argument to list_lru_from_kmem()

This is just refactoring to allow the next patches to have memcg pointer
in list_lru_from_kmem().

Link: http://lkml.kernel.org/r/153063060664.1818.9541345386733498582.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/list_lru.c b/mm/list_lru.c
index 5aebbb9..1fc5be7 100644 (file)
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -65,18 +65,24 @@ static __always_inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr)
 }
 
 static inline struct list_lru_one *
-list_lru_from_kmem(struct list_lru_node *nlru, void *ptr)
+list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
+                  struct mem_cgroup **memcg_ptr)
 {
-       struct mem_cgroup *memcg;
+       struct list_lru_one *l = &nlru->lru;
+       struct mem_cgroup *memcg = NULL;
 
        if (!nlru->memcg_lrus)
-               return &nlru->lru;
+               goto out;
 
        memcg = mem_cgroup_from_kmem(ptr);
        if (!memcg)
-               return &nlru->lru;
+               goto out;
 
-       return list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
+       l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
+out:
+       if (memcg_ptr)
+               *memcg_ptr = memcg;
+       return l;
 }
 #else
 static void list_lru_register(struct list_lru *lru)
@@ -99,8 +105,11 @@ list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
 }
 
 static inline struct list_lru_one *
-list_lru_from_kmem(struct list_lru_node *nlru, void *ptr)
+list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
+                  struct mem_cgroup **memcg_ptr)
 {
+       if (memcg_ptr)
+               *memcg_ptr = NULL;
        return &nlru->lru;
 }
 #endif /* CONFIG_MEMCG_KMEM */
@@ -113,7 +122,7 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item)
 
        spin_lock(&nlru->lock);
        if (list_empty(item)) {
-               l = list_lru_from_kmem(nlru, item);
+               l = list_lru_from_kmem(nlru, item, NULL);
                list_add_tail(item, &l->list);
                l->nr_items++;
                nlru->nr_items++;
@@ -133,7 +142,7 @@ bool list_lru_del(struct list_lru *lru, struct list_head *item)
 
        spin_lock(&nlru->lock);
        if (!list_empty(item)) {
-               l = list_lru_from_kmem(nlru, item);
+               l = list_lru_from_kmem(nlru, item, NULL);
                list_del_init(item);
                l->nr_items--;
                nlru->nr_items--;