From 024914477e15ef8b17f271ec47f1bb8a589f0806 Mon Sep 17 00:00:00 2001 From: Daisuke Nishimura Date: Wed, 10 Mar 2010 15:22:17 -0800 Subject: memcg: move charges of anonymous swap This patch is another core part of this move-charge-at-task-migration feature. It enables moving charges of anonymous swaps. To move the charge of swap, we need to exchange swap_cgroup's record. In current implementation, swap_cgroup's record is protected by: - page lock: if the entry is on swap cache. - swap_lock: if the entry is not on swap cache. This works well in usual swap-in/out activity. But this behavior make the feature of moving swap charge check many conditions to exchange swap_cgroup's record safely. So I changed modification of swap_cgroup's recored(swap_cgroup_record()) to use xchg, and define a new function to cmpxchg swap_cgroup's record. This patch also enables moving charge of non pte_present but not uncharged swap caches, which can be exist on swap-out path, by getting the target pages via find_get_page() as do_mincore() does. [kosaki.motohiro@jp.fujitsu.com: fix ia64 build] [akpm@linux-foundation.org: fix typos] Signed-off-by: Daisuke Nishimura Cc: Balbir Singh Acked-by: KAMEZAWA Hiroyuki Cc: Li Zefan Cc: Paul Menage Cc: Daisuke Nishimura Signed-off-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page_cgroup.h | 2 ++ include/linux/swap.h | 9 +++++++++ 2 files changed, 11 insertions(+) (limited to 'include') diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h index b0e4eb126236..30b08136fdf3 100644 --- a/include/linux/page_cgroup.h +++ b/include/linux/page_cgroup.h @@ -118,6 +118,8 @@ static inline void __init page_cgroup_init_flatmem(void) #include #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP +extern unsigned short swap_cgroup_cmpxchg(swp_entry_t ent, + unsigned short old, unsigned short new); extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id); extern unsigned short lookup_swap_cgroup(swp_entry_t ent); extern int swap_cgroup_swapon(int type, unsigned long max_pages); diff --git a/include/linux/swap.h b/include/linux/swap.h index a2602a8207a6..1f59d9340c4d 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -355,6 +355,7 @@ static inline void disable_swap_token(void) #ifdef CONFIG_CGROUP_MEM_RES_CTLR extern void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout); +extern int mem_cgroup_count_swap_user(swp_entry_t ent, struct page **pagep); #else static inline void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) @@ -485,6 +486,14 @@ mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) { } +#ifdef CONFIG_CGROUP_MEM_RES_CTLR +static inline int +mem_cgroup_count_swap_user(swp_entry_t ent, struct page **pagep) +{ + return 0; +} +#endif + #endif /* CONFIG_SWAP */ #endif /* __KERNEL__*/ #endif /* _LINUX_SWAP_H */ -- cgit v1.2.2