From 52d4b9ac0b985168009c2a57098324e67bae171f Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Sat, 18 Oct 2008 20:28:16 -0700 Subject: memcg: allocate all page_cgroup at boot Allocate all page_cgroup at boot and remove page_cgroup poitner from struct page. This patch adds an interface as struct page_cgroup *lookup_page_cgroup(struct page*) All FLATMEM/DISCONTIGMEM/SPARSEMEM and MEMORY_HOTPLUG is supported. Remove page_cgroup pointer reduces the amount of memory by - 4 bytes per PAGE_SIZE. - 8 bytes per PAGE_SIZE if memory controller is disabled. (even if configured.) On usual 8GB x86-32 server, this saves 8MB of NORMAL_ZONE memory. On my x86-64 server with 48GB of memory, this saves 96MB of memory. I think this reduction makes sense. By pre-allocation, kmalloc/kfree in charge/uncharge are removed. This means - we're not necessary to be afraid of kmalloc faiulre. (this can happen because of gfp_mask type.) - we can avoid calling kmalloc/kfree. - we can avoid allocating tons of small objects which can be fragmented. - we can know what amount of memory will be used for this extra-lru handling. I added printk message as "allocated %ld bytes of page_cgroup" "please try cgroup_disable=memory option if you don't want" maybe enough informative for users. Signed-off-by: KAMEZAWA Hiroyuki Reviewed-by: Balbir Singh Cc: Daisuke Nishimura Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page_cgroup.h | 103 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 include/linux/page_cgroup.h (limited to 'include/linux/page_cgroup.h') diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h new file mode 100644 index 000000000000..0fd39f2231ec --- /dev/null +++ b/include/linux/page_cgroup.h @@ -0,0 +1,103 @@ +#ifndef __LINUX_PAGE_CGROUP_H +#define __LINUX_PAGE_CGROUP_H + +#ifdef CONFIG_CGROUP_MEM_RES_CTLR +#include +/* + * Page Cgroup can be considered as an extended mem_map. + * A page_cgroup page is associated with every page descriptor. The + * page_cgroup helps us identify information about the cgroup + * All page cgroups are allocated at boot or memory hotplug event, + * then the page cgroup for pfn always exists. + */ +struct page_cgroup { + unsigned long flags; + struct mem_cgroup *mem_cgroup; + struct page *page; + struct list_head lru; /* per cgroup LRU list */ +}; + +void __init pgdat_page_cgroup_init(struct pglist_data *pgdat); +void __init page_cgroup_init(void); +struct page_cgroup *lookup_page_cgroup(struct page *page); + +enum { + /* flags for mem_cgroup */ + PCG_LOCK, /* page cgroup is locked */ + PCG_CACHE, /* charged as cache */ + PCG_USED, /* this object is in use. */ + /* flags for LRU placement */ + PCG_ACTIVE, /* page is active in this cgroup */ + PCG_FILE, /* page is file system backed */ + PCG_UNEVICTABLE, /* page is unevictableable */ +}; + +#define TESTPCGFLAG(uname, lname) \ +static inline int PageCgroup##uname(struct page_cgroup *pc) \ + { return test_bit(PCG_##lname, &pc->flags); } + +#define SETPCGFLAG(uname, lname) \ +static inline void SetPageCgroup##uname(struct page_cgroup *pc)\ + { set_bit(PCG_##lname, &pc->flags); } + +#define CLEARPCGFLAG(uname, lname) \ +static inline void ClearPageCgroup##uname(struct page_cgroup *pc) \ + { clear_bit(PCG_##lname, &pc->flags); } + +/* Cache flag is set only once (at allocation) */ +TESTPCGFLAG(Cache, CACHE) + +TESTPCGFLAG(Used, USED) +CLEARPCGFLAG(Used, USED) + +/* LRU management flags (from global-lru definition) */ +TESTPCGFLAG(File, FILE) +SETPCGFLAG(File, FILE) +CLEARPCGFLAG(File, FILE) + +TESTPCGFLAG(Active, ACTIVE) +SETPCGFLAG(Active, ACTIVE) +CLEARPCGFLAG(Active, ACTIVE) + +TESTPCGFLAG(Unevictable, UNEVICTABLE) +SETPCGFLAG(Unevictable, UNEVICTABLE) +CLEARPCGFLAG(Unevictable, UNEVICTABLE) + +static inline int page_cgroup_nid(struct page_cgroup *pc) +{ + return page_to_nid(pc->page); +} + +static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc) +{ + return page_zonenum(pc->page); +} + +static inline void lock_page_cgroup(struct page_cgroup *pc) +{ + bit_spin_lock(PCG_LOCK, &pc->flags); +} + +static inline int trylock_page_cgroup(struct page_cgroup *pc) +{ + return bit_spin_trylock(PCG_LOCK, &pc->flags); +} + +static inline void unlock_page_cgroup(struct page_cgroup *pc) +{ + bit_spin_unlock(PCG_LOCK, &pc->flags); +} + +#else /* CONFIG_CGROUP_MEM_RES_CTLR */ +struct page_cgroup; + +static inline void pgdat_page_cgroup_init(struct pglist_data *pgdat) +{ +} + +static inline struct page_cgroup *lookup_page_cgroup(struct page *page) +{ + return NULL; +} +#endif +#endif -- cgit v1.2.3-59-g8ed1b