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 --- mm/Makefile | 3 +- mm/memcontrol.c | 247 ++++++++++++++++++------------------------------------- mm/page_alloc.c | 12 +-- mm/page_cgroup.c | 237 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 321 insertions(+), 178 deletions(-) create mode 100644 mm/page_cgroup.c (limited to 'mm') diff --git a/mm/Makefile b/mm/Makefile index da4ccf015ae..c06b45a1ff5 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -33,5 +33,4 @@ obj-$(CONFIG_FS_XIP) += filemap_xip.o obj-$(CONFIG_MIGRATION) += migrate.o obj-$(CONFIG_SMP) += allocpercpu.o obj-$(CONFIG_QUICKLIST) += quicklist.o -obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o - +obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 031682e7ef0..d4a92b63e98 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -33,11 +33,11 @@ #include #include #include +#include #include struct cgroup_subsys mem_cgroup_subsys __read_mostly; -static struct kmem_cache *page_cgroup_cache __read_mostly; #define MEM_CGROUP_RECLAIM_RETRIES 5 /* @@ -135,79 +135,6 @@ struct mem_cgroup { }; static struct mem_cgroup init_mem_cgroup; -/* - * We use the lower bit of the page->page_cgroup pointer as a bit spin - * lock. We need to ensure that page->page_cgroup is at least two - * byte aligned (based on comments from Nick Piggin). But since - * bit_spin_lock doesn't actually set that lock bit in a non-debug - * uniprocessor kernel, we should avoid setting it here too. - */ -#define PAGE_CGROUP_LOCK_BIT 0x0 -#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) -#define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT) -#else -#define PAGE_CGROUP_LOCK 0x0 -#endif - -/* - * A page_cgroup page is associated with every page descriptor. The - * page_cgroup helps us identify information about the cgroup - */ -struct page_cgroup { - struct list_head lru; /* per cgroup LRU list */ - struct page *page; - struct mem_cgroup *mem_cgroup; - unsigned long flags; -}; - -enum { - /* flags for mem_cgroup */ - PCG_CACHE, /* charged as cache */ - /* 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) - -/* 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 int page_cgroup_nid(struct page_cgroup *pc) -{ - return page_to_nid(pc->page); -} - -static enum zone_type page_cgroup_zid(struct page_cgroup *pc) -{ - return page_zonenum(pc->page); -} - enum charge_type { MEM_CGROUP_CHARGE_TYPE_CACHE = 0, MEM_CGROUP_CHARGE_TYPE_MAPPED, @@ -216,12 +143,18 @@ enum charge_type { NR_CHARGE_TYPE, }; +/* only for here (for easy reading.) */ +#define PCGF_CACHE (1UL << PCG_CACHE) +#define PCGF_USED (1UL << PCG_USED) +#define PCGF_ACTIVE (1UL << PCG_ACTIVE) +#define PCGF_LOCK (1UL << PCG_LOCK) +#define PCGF_FILE (1UL << PCG_FILE) static const unsigned long pcg_default_flags[NR_CHARGE_TYPE] = { - ((1 << PCG_CACHE) | (1 << PCG_FILE)), - ((1 << PCG_ACTIVE)), - ((1 << PCG_ACTIVE) | (1 << PCG_CACHE)), - 0, + PCGF_CACHE | PCGF_FILE | PCGF_USED | PCGF_LOCK, /* File Cache */ + PCGF_ACTIVE | PCGF_USED | PCGF_LOCK, /* Anon */ + PCGF_ACTIVE | PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */ + 0, /* FORCE */ }; /* @@ -303,37 +236,6 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) struct mem_cgroup, css); } -static inline int page_cgroup_locked(struct page *page) -{ - return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); -} - -static void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc) -{ - VM_BUG_ON(!page_cgroup_locked(page)); - page->page_cgroup = ((unsigned long)pc | PAGE_CGROUP_LOCK); -} - -struct page_cgroup *page_get_page_cgroup(struct page *page) -{ - return (struct page_cgroup *) (page->page_cgroup & ~PAGE_CGROUP_LOCK); -} - -static void lock_page_cgroup(struct page *page) -{ - bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); -} - -static int try_lock_page_cgroup(struct page *page) -{ - return bit_spin_trylock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); -} - -static void unlock_page_cgroup(struct page *page) -{ - bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup); -} - static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone *mz, struct page_cgroup *pc) { @@ -436,17 +338,16 @@ void mem_cgroup_move_lists(struct page *page, enum lru_list lru) * safely get to page_cgroup without it, so just try_lock it: * mem_cgroup_isolate_pages allows for page left on wrong list. */ - if (!try_lock_page_cgroup(page)) + pc = lookup_page_cgroup(page); + if (!trylock_page_cgroup(pc)) return; - - pc = page_get_page_cgroup(page); - if (pc) { + if (pc && PageCgroupUsed(pc)) { mz = page_cgroup_zoneinfo(pc); spin_lock_irqsave(&mz->lru_lock, flags); __mem_cgroup_move_lists(pc, lru); spin_unlock_irqrestore(&mz->lru_lock, flags); } - unlock_page_cgroup(page); + unlock_page_cgroup(pc); } /* @@ -533,6 +434,8 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, list_for_each_entry_safe_reverse(pc, tmp, src, lru) { if (scan >= nr_to_scan) break; + if (unlikely(!PageCgroupUsed(pc))) + continue; page = pc->page; if (unlikely(!PageLRU(page))) @@ -576,26 +479,27 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, { struct mem_cgroup *mem; struct page_cgroup *pc; - unsigned long flags; unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES; struct mem_cgroup_per_zone *mz; + unsigned long flags; - pc = kmem_cache_alloc(page_cgroup_cache, gfp_mask); - if (unlikely(pc == NULL)) - goto err; - + pc = lookup_page_cgroup(page); + /* can happen at boot */ + if (unlikely(!pc)) + return 0; + prefetchw(pc); /* * We always charge the cgroup the mm_struct belongs to. * The mm_struct's mem_cgroup changes on task migration if the * thread group leader migrates. It's possible that mm is not * set, if so charge the init_mm (happens for pagecache usage). */ + if (likely(!memcg)) { rcu_read_lock(); mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); if (unlikely(!mem)) { rcu_read_unlock(); - kmem_cache_free(page_cgroup_cache, pc); return 0; } /* @@ -631,36 +535,33 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, } } + + lock_page_cgroup(pc); + if (unlikely(PageCgroupUsed(pc))) { + unlock_page_cgroup(pc); + res_counter_uncharge(&mem->res, PAGE_SIZE); + css_put(&mem->css); + + goto done; + } pc->mem_cgroup = mem; - pc->page = page; /* * If a page is accounted as a page cache, insert to inactive list. * If anon, insert to active list. */ pc->flags = pcg_default_flags[ctype]; - lock_page_cgroup(page); - if (unlikely(page_get_page_cgroup(page))) { - unlock_page_cgroup(page); - res_counter_uncharge(&mem->res, PAGE_SIZE); - css_put(&mem->css); - kmem_cache_free(page_cgroup_cache, pc); - goto done; - } - page_assign_page_cgroup(page, pc); - mz = page_cgroup_zoneinfo(pc); + spin_lock_irqsave(&mz->lru_lock, flags); __mem_cgroup_add_list(mz, pc); spin_unlock_irqrestore(&mz->lru_lock, flags); + unlock_page_cgroup(pc); - unlock_page_cgroup(page); done: return 0; out: css_put(&mem->css); - kmem_cache_free(page_cgroup_cache, pc); -err: return -ENOMEM; } @@ -668,7 +569,8 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) { if (mem_cgroup_subsys.disabled) return 0; - + if (PageCompound(page)) + return 0; /* * If already mapped, we don't have to account. * If page cache, page->mapping has address_space. @@ -689,7 +591,8 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, { if (mem_cgroup_subsys.disabled) return 0; - + if (PageCompound(page)) + return 0; /* * Corner case handling. This is called from add_to_page_cache() * in usual. But some FS (shmem) precharges this page before calling it @@ -702,15 +605,16 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, if (!(gfp_mask & __GFP_WAIT)) { struct page_cgroup *pc; - lock_page_cgroup(page); - pc = page_get_page_cgroup(page); - if (pc) { - VM_BUG_ON(pc->page != page); - VM_BUG_ON(!pc->mem_cgroup); - unlock_page_cgroup(page); + + pc = lookup_page_cgroup(page); + if (!pc) + return 0; + lock_page_cgroup(pc); + if (PageCgroupUsed(pc)) { + unlock_page_cgroup(pc); return 0; } - unlock_page_cgroup(page); + unlock_page_cgroup(pc); } if (unlikely(!mm)) @@ -741,37 +645,39 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) /* * Check if our page_cgroup is valid */ - lock_page_cgroup(page); - pc = page_get_page_cgroup(page); - if (unlikely(!pc)) - goto unlock; - - VM_BUG_ON(pc->page != page); + pc = lookup_page_cgroup(page); + if (unlikely(!pc || !PageCgroupUsed(pc))) + return; - if ((ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED) - && ((PageCgroupCache(pc) || page_mapped(page)))) - goto unlock; + lock_page_cgroup(pc); + if ((ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED && page_mapped(page)) + || !PageCgroupUsed(pc)) { + /* This happens at race in zap_pte_range() and do_swap_page()*/ + unlock_page_cgroup(pc); + return; + } + ClearPageCgroupUsed(pc); + mem = pc->mem_cgroup; mz = page_cgroup_zoneinfo(pc); spin_lock_irqsave(&mz->lru_lock, flags); __mem_cgroup_remove_list(mz, pc); spin_unlock_irqrestore(&mz->lru_lock, flags); + unlock_page_cgroup(pc); - page_assign_page_cgroup(page, NULL); - unlock_page_cgroup(page); - - mem = pc->mem_cgroup; res_counter_uncharge(&mem->res, PAGE_SIZE); css_put(&mem->css); - kmem_cache_free(page_cgroup_cache, pc); return; -unlock: - unlock_page_cgroup(page); } void mem_cgroup_uncharge_page(struct page *page) { + /* early check. */ + if (page_mapped(page)) + return; + if (page->mapping && !PageAnon(page)) + return; __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); } @@ -795,9 +701,9 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage) if (mem_cgroup_subsys.disabled) return 0; - lock_page_cgroup(page); - pc = page_get_page_cgroup(page); - if (pc) { + pc = lookup_page_cgroup(page); + lock_page_cgroup(pc); + if (PageCgroupUsed(pc)) { mem = pc->mem_cgroup; css_get(&mem->css); if (PageCgroupCache(pc)) { @@ -807,7 +713,7 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage) ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; } } - unlock_page_cgroup(page); + unlock_page_cgroup(pc); if (mem) { ret = mem_cgroup_charge_common(newpage, NULL, GFP_KERNEL, ctype, mem); @@ -832,7 +738,7 @@ void mem_cgroup_end_migration(struct page *newpage) */ if (!newpage->mapping) __mem_cgroup_uncharge_common(newpage, - MEM_CGROUP_CHARGE_TYPE_FORCE); + MEM_CGROUP_CHARGE_TYPE_FORCE); else if (PageAnon(newpage)) mem_cgroup_uncharge_page(newpage); } @@ -918,6 +824,8 @@ static void mem_cgroup_force_empty_list(struct mem_cgroup *mem, while (!list_empty(list)) { pc = list_entry(list->prev, struct page_cgroup, lru); page = pc->page; + if (!PageCgroupUsed(pc)) + break; get_page(page); spin_unlock_irqrestore(&mz->lru_lock, flags); /* @@ -932,8 +840,10 @@ static void mem_cgroup_force_empty_list(struct mem_cgroup *mem, count = FORCE_UNCHARGE_BATCH; cond_resched(); } - } else - cond_resched(); + } else { + spin_lock_irqsave(&mz->lru_lock, flags); + break; + } spin_lock_irqsave(&mz->lru_lock, flags); } spin_unlock_irqrestore(&mz->lru_lock, flags); @@ -957,6 +867,8 @@ static int mem_cgroup_force_empty(struct mem_cgroup *mem) while (mem->res.usage > 0) { if (atomic_read(&mem->css.cgroup->count) > 0) goto out; + /* This is for making all *used* pages to be on LRU. */ + lru_add_drain_all(); for_each_node_state(node, N_POSSIBLE) for (zid = 0; zid < MAX_NR_ZONES; zid++) { struct mem_cgroup_per_zone *mz; @@ -965,6 +877,7 @@ static int mem_cgroup_force_empty(struct mem_cgroup *mem) for_each_lru(l) mem_cgroup_force_empty_list(mem, mz, l); } + cond_resched(); } ret = 0; out: @@ -1175,8 +1088,8 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) int node; if (unlikely((cont->parent) == NULL)) { + page_cgroup_init(); mem = &init_mem_cgroup; - page_cgroup_cache = KMEM_CACHE(page_cgroup, SLAB_PANIC); } else { mem = mem_cgroup_alloc(); if (!mem) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index f2fc44ec1d4..d0a240fbb8b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -44,7 +44,7 @@ #include #include #include -#include +#include #include #include @@ -223,17 +223,12 @@ static inline int bad_range(struct zone *zone, struct page *page) static void bad_page(struct page *page) { - void *pc = page_get_page_cgroup(page); - printk(KERN_EMERG "Bad page state in process '%s'\n" KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n", current->comm, page, (int)(2*sizeof(unsigned long)), (unsigned long)page->flags, page->mapping, page_mapcount(page), page_count(page)); - if (pc) { - printk(KERN_EMERG "cgroup:%p\n", pc); - page_reset_bad_cgroup(page); - } + printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n" KERN_EMERG "Backtrace:\n"); dump_stack(); @@ -457,7 +452,6 @@ static inline int free_pages_check(struct page *page) free_page_mlock(page); if (unlikely(page_mapcount(page) | (page->mapping != NULL) | - (page_get_page_cgroup(page) != NULL) | (page_count(page) != 0) | (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) bad_page(page); @@ -603,7 +597,6 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) { if (unlikely(page_mapcount(page) | (page->mapping != NULL) | - (page_get_page_cgroup(page) != NULL) | (page_count(page) != 0) | (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) bad_page(page); @@ -3438,6 +3431,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, pgdat->nr_zones = 0; init_waitqueue_head(&pgdat->kswapd_wait); pgdat->kswapd_max_order = 0; + pgdat_page_cgroup_init(pgdat); for (j = 0; j < MAX_NR_ZONES; j++) { struct zone *zone = pgdat->node_zones + j; diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c new file mode 100644 index 00000000000..5d86550701f --- /dev/null +++ b/mm/page_cgroup.c @@ -0,0 +1,237 @@ +#include +#include +#include +#include +#include +#include +#include + +static void __meminit +__init_page_cgroup(struct page_cgroup *pc, unsigned long pfn) +{ + pc->flags = 0; + pc->mem_cgroup = NULL; + pc->page = pfn_to_page(pfn); +} +static unsigned long total_usage; + +#if !defined(CONFIG_SPARSEMEM) + + +void __init pgdat_page_cgroup_init(struct pglist_data *pgdat) +{ + pgdat->node_page_cgroup = NULL; +} + +struct page_cgroup *lookup_page_cgroup(struct page *page) +{ + unsigned long pfn = page_to_pfn(page); + unsigned long offset; + struct page_cgroup *base; + + base = NODE_DATA(page_to_nid(page))->node_page_cgroup; + if (unlikely(!base)) + return NULL; + + offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn; + return base + offset; +} + +static int __init alloc_node_page_cgroup(int nid) +{ + struct page_cgroup *base, *pc; + unsigned long table_size; + unsigned long start_pfn, nr_pages, index; + + start_pfn = NODE_DATA(nid)->node_start_pfn; + nr_pages = NODE_DATA(nid)->node_spanned_pages; + + table_size = sizeof(struct page_cgroup) * nr_pages; + + base = __alloc_bootmem_node_nopanic(NODE_DATA(nid), + table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS)); + if (!base) + return -ENOMEM; + for (index = 0; index < nr_pages; index++) { + pc = base + index; + __init_page_cgroup(pc, start_pfn + index); + } + NODE_DATA(nid)->node_page_cgroup = base; + total_usage += table_size; + return 0; +} + +void __init page_cgroup_init(void) +{ + + int nid, fail; + + for_each_online_node(nid) { + fail = alloc_node_page_cgroup(nid); + if (fail) + goto fail; + } + printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage); + printk(KERN_INFO "please try cgroup_disable=memory option if you" + " don't want\n"); + return; +fail: + printk(KERN_CRIT "allocation of page_cgroup was failed.\n"); + printk(KERN_CRIT "please try cgroup_disable=memory boot option\n"); + panic("Out of memory"); +} + +#else /* CONFIG_FLAT_NODE_MEM_MAP */ + +struct page_cgroup *lookup_page_cgroup(struct page *page) +{ + unsigned long pfn = page_to_pfn(page); + struct mem_section *section = __pfn_to_section(pfn); + + return section->page_cgroup + pfn; +} + +int __meminit init_section_page_cgroup(unsigned long pfn) +{ + struct mem_section *section; + struct page_cgroup *base, *pc; + unsigned long table_size; + int nid, index; + + section = __pfn_to_section(pfn); + + if (section->page_cgroup) + return 0; + + nid = page_to_nid(pfn_to_page(pfn)); + + table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION; + base = kmalloc_node(table_size, GFP_KERNEL, nid); + if (!base) + base = vmalloc_node(table_size, nid); + + if (!base) { + printk(KERN_ERR "page cgroup allocation failure\n"); + return -ENOMEM; + } + + for (index = 0; index < PAGES_PER_SECTION; index++) { + pc = base + index; + __init_page_cgroup(pc, pfn + index); + } + + section = __pfn_to_section(pfn); + section->page_cgroup = base - pfn; + total_usage += table_size; + return 0; +} +#ifdef CONFIG_MEMORY_HOTPLUG +void __free_page_cgroup(unsigned long pfn) +{ + struct mem_section *ms; + struct page_cgroup *base; + + ms = __pfn_to_section(pfn); + if (!ms || !ms->page_cgroup) + return; + base = ms->page_cgroup + pfn; + ms->page_cgroup = NULL; + if (is_vmalloc_addr(base)) + vfree(base); + else + kfree(base); +} + +int online_page_cgroup(unsigned long start_pfn, + unsigned long nr_pages, + int nid) +{ + unsigned long start, end, pfn; + int fail = 0; + + start = start_pfn & (PAGES_PER_SECTION - 1); + end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION); + + for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) { + if (!pfn_present(pfn)) + continue; + fail = init_section_page_cgroup(pfn); + } + if (!fail) + return 0; + + /* rollback */ + for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) + __free_page_cgroup(pfn); + + return -ENOMEM; +} + +int offline_page_cgroup(unsigned long start_pfn, + unsigned long nr_pages, int nid) +{ + unsigned long start, end, pfn; + + start = start_pfn & (PAGES_PER_SECTION - 1); + end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION); + + for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) + __free_page_cgroup(pfn); + return 0; + +} + +static int page_cgroup_callback(struct notifier_block *self, + unsigned long action, void *arg) +{ + struct memory_notify *mn = arg; + int ret = 0; + switch (action) { + case MEM_GOING_ONLINE: + ret = online_page_cgroup(mn->start_pfn, + mn->nr_pages, mn->status_change_nid); + break; + case MEM_CANCEL_ONLINE: + case MEM_OFFLINE: + offline_page_cgroup(mn->start_pfn, + mn->nr_pages, mn->status_change_nid); + break; + case MEM_GOING_OFFLINE: + break; + case MEM_ONLINE: + case MEM_CANCEL_OFFLINE: + break; + } + ret = notifier_from_errno(ret); + return ret; +} + +#endif + +void __init page_cgroup_init(void) +{ + unsigned long pfn; + int fail = 0; + + for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) { + if (!pfn_present(pfn)) + continue; + fail = init_section_page_cgroup(pfn); + } + if (fail) { + printk(KERN_CRIT "try cgroup_disable=memory boot option\n"); + panic("Out of memory"); + } else { + hotplug_memory_notifier(page_cgroup_callback, 0); + } + printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage); + printk(KERN_INFO "please try cgroup_disable=memory option if you don't" + " want\n"); +} + +void __init pgdat_page_cgroup_init(struct pglist_data *pgdat) +{ + return; +} + +#endif -- cgit v1.2.3