From dac23b0d0513916498d40412818bd2c581b365f7 Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.cz>
Date: Thu, 5 Apr 2012 14:25:16 -0700
Subject: [PATCH] memcg swap: use mem_cgroup_uncharge_swap fix
Although mem_cgroup_uncharge_swap has an empty placeholder for
!CONFIG_CGROUP_MEM_RES_CTLR_SWAP the definition is placed in the
CONFIG_SWAP ifdef block so we are missing the same definition for
!CONFIG_SWAP which implies !CONFIG_CGROUP_MEM_RES_CTLR_SWAP.
This has not been an issue before, because mem_cgroup_uncharge_swap was
not called from !CONFIG_SWAP context. But Hugh Dickins has a cleanup
patch to call __mem_cgroup_commit_charge_swapin which is defined also
for !CONFIG_SWAP.
Let's move both the empty definition and declaration outside of the
CONFIG_SWAP block to avoid the following compilation error:
mm/memcontrol.c: In function '__mem_cgroup_commit_charge_swapin':
mm/memcontrol.c:2837: error: implicit declaration of function 'mem_cgroup_uncharge_swap'
if CONFIG_SWAP is disabled.
Reported-by: David Rientjes <rientjes@google.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/swap.h | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 8dc0ea7caf02..b1fd5c7925fe 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -305,6 +305,13 @@ static inline int mem_cgroup_swappiness(struct mem_cgroup *mem)
return vm_swappiness;
}
#endif
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+extern void mem_cgroup_uncharge_swap(swp_entry_t ent);
+#else
+static inline void mem_cgroup_uncharge_swap(swp_entry_t ent)
+{
+}
+#endif
#ifdef CONFIG_SWAP
/* linux/mm/page_io.c */
extern int swap_readpage(struct page *);
@@ -375,13 +382,6 @@ mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
{
}
#endif
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
-extern void mem_cgroup_uncharge_swap(swp_entry_t ent);
-#else
-static inline void mem_cgroup_uncharge_swap(swp_entry_t ent)
-{
-}
-#endif
#else /* CONFIG_SWAP */
--
2.20.1