From dac23b0d0513916498d40412818bd2c581b365f7 Mon Sep 17 00:00:00 2001 From: Michal Hocko 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 Signed-off-by: Michal Hocko Cc: Hugh Dickins Cc: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 */ -- GitLab