[GitHub/mt8127/android_kernel_alcatel_ttab.git] / mm / page_cgroup.c

#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/bootmem.h>
#include <linux/bit_spinlock.h>
#include <linux/page_cgroup.h>
#include <linux/hash.h>
#include <linux/slab.h>
#include <linux/memory.h>
#include <linux/vmalloc.h>
#include <linux/cgroup.h>
#include <linux/swapops.h>
#include <linux/kmemleak.h>

static void __meminit init_page_cgroup(struct page_cgroup *pc, unsigned long id)
{
	pc->flags = 0;
	set_page_cgroup_array_id(pc, id);
	pc->mem_cgroup = NULL;
	INIT_LIST_HEAD(&pc->lru);
}
static unsigned long total_usage;

#if !defined(CONFIG_SPARSEMEM)


void __meminit 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;
}

struct page *lookup_cgroup_page(struct page_cgroup *pc)
{
	unsigned long pfn;
	struct page *page;
	pg_data_t *pgdat;

	pgdat = NODE_DATA(page_cgroup_array_id(pc));
	pfn = pc - pgdat->node_page_cgroup + pgdat->node_start_pfn;
	page = pfn_to_page(pfn);
	VM_BUG_ON(pc != lookup_page_cgroup(page));
	return page;
}

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;

	if (!nr_pages)
		return 0;

	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, nid);
	}
	NODE_DATA(nid)->node_page_cgroup = base;
	total_usage += table_size;
	return 0;
}

void __init page_cgroup_init_flatmem(void)
{

	int nid, fail;

	if (mem_cgroup_disabled())
		return;

	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 memory cgroups\n");
	return;
fail:
	printk(KERN_CRIT "allocation of page_cgroup 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);

	if (!section->page_cgroup)
		return NULL;
	return section->page_cgroup + pfn;
}

struct page *lookup_cgroup_page(struct page_cgroup *pc)
{
	struct mem_section *section;
	struct page *page;
	unsigned long nr;

	nr = page_cgroup_array_id(pc);
	section = __nr_to_section(nr);
	page = pfn_to_page(pc - section->page_cgroup);
	VM_BUG_ON(pc != lookup_page_cgroup(page));
	return page;
}

/* __alloc_bootmem...() is protected by !slab_available() */
static int __init_refok init_section_page_cgroup(unsigned long pfn)
{
	struct page_cgroup *base, *pc;
	struct mem_section *section;
	unsigned long table_size;
	unsigned long nr;
	int nid, index;

	nr = pfn_to_section_nr(pfn);
	section = __nr_to_section(nr);

	if (section->page_cgroup)
		return 0;

	nid = page_to_nid(pfn_to_page(pfn));
	table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
	VM_BUG_ON(!slab_is_available());
	if (node_state(nid, N_HIGH_MEMORY)) {
		base = kmalloc_node(table_size,
				    GFP_KERNEL | __GFP_NOWARN, nid);
		if (!base)
			base = vmalloc_node(table_size, nid);
	} else {
		base = kmalloc(table_size, GFP_KERNEL | __GFP_NOWARN);
		if (!base)
			base = vmalloc(table_size);
	}
	/*
	 * The value stored in section->page_cgroup is (base - pfn)
	 * and it does not point to the memory block allocated above,
	 * causing kmemleak false positives.
	 */
	kmemleak_not_leak(base);

	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, nr);
	}

	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;
	if (is_vmalloc_addr(base)) {
		vfree(base);
		ms->page_cgroup = NULL;
	} else {
		struct page *page = virt_to_page(base);
		if (!PageReserved(page)) { /* Is bootmem ? */
			kfree(base);
			ms->page_cgroup = NULL;
		}
	}
}

int __meminit 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 __meminit 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 __meminit 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_OFFLINE:
		offline_page_cgroup(mn->start_pfn,
				mn->nr_pages, mn->status_change_nid);
		break;
	case MEM_CANCEL_ONLINE:
	case MEM_GOING_OFFLINE:
		break;
	case MEM_ONLINE:
	case MEM_CANCEL_OFFLINE:
		break;
	}

	return notifier_from_errno(ret);
}

#endif

void __init page_cgroup_init(void)
{
	unsigned long pfn;
	int fail = 0;

	if (mem_cgroup_disabled())
		return;

	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 memory cgroups\n");
}

void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
{
	return;
}

#endif


#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP

static DEFINE_MUTEX(swap_cgroup_mutex);
struct swap_cgroup_ctrl {
	struct page **map;
	unsigned long length;
	spinlock_t	lock;
};

struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];

struct swap_cgroup {
	unsigned short		id;
};
#define SC_PER_PAGE	(PAGE_SIZE/sizeof(struct swap_cgroup))
#define SC_POS_MASK	(SC_PER_PAGE - 1)

/*
 * SwapCgroup implements "lookup" and "exchange" operations.
 * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
 * against SwapCache. At swap_free(), this is accessed directly from swap.
 *
 * This means,
 *  - we have no race in "exchange" when we're accessed via SwapCache because
 *    SwapCache(and its swp_entry) is under lock.
 *  - When called via swap_free(), there is no user of this entry and no race.
 * Then, we don't need lock around "exchange".
 *
 * TODO: we can push these buffers out to HIGHMEM.
 */

/*
 * allocate buffer for swap_cgroup.
 */
static int swap_cgroup_prepare(int type)
{
	struct page *page;
	struct swap_cgroup_ctrl *ctrl;
	unsigned long idx, max;

	ctrl = &swap_cgroup_ctrl[type];

	for (idx = 0; idx < ctrl->length; idx++) {
		page = alloc_page(GFP_KERNEL | __GFP_ZERO);
		if (!page)
			goto not_enough_page;
		ctrl->map[idx] = page;
	}
	return 0;
not_enough_page:
	max = idx;
	for (idx = 0; idx < max; idx++)
		__free_page(ctrl->map[idx]);

	return -ENOMEM;
}

/**
 * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
 * @end: swap entry to be cmpxchged
 * @old: old id
 * @new: new id
 *
 * Returns old id at success, 0 at failure.
 * (There is no mem_cgroup useing 0 as its id)
 */
unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
					unsigned short old, unsigned short new)
{
	int type = swp_type(ent);
	unsigned long offset = swp_offset(ent);
	unsigned long idx = offset / SC_PER_PAGE;
	unsigned long pos = offset & SC_POS_MASK;
	struct swap_cgroup_ctrl *ctrl;
	struct page *mappage;
	struct swap_cgroup *sc;
	unsigned long flags;
	unsigned short retval;

	ctrl = &swap_cgroup_ctrl[type];

	mappage = ctrl->map[idx];
	sc = page_address(mappage);
	sc += pos;
	spin_lock_irqsave(&ctrl->lock, flags);
	retval = sc->id;
	if (retval == old)
		sc->id = new;
	else
		retval = 0;
	spin_unlock_irqrestore(&ctrl->lock, flags);
	return retval;
}

/**
 * swap_cgroup_record - record mem_cgroup for this swp_entry.
 * @ent: swap entry to be recorded into
 * @mem: mem_cgroup to be recorded
 *
 * Returns old value at success, 0 at failure.
 * (Of course, old value can be 0.)
 */
unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
{
	int type = swp_type(ent);
	unsigned long offset = swp_offset(ent);
	unsigned long idx = offset / SC_PER_PAGE;
	unsigned long pos = offset & SC_POS_MASK;
	struct swap_cgroup_ctrl *ctrl;
	struct page *mappage;
	struct swap_cgroup *sc;
	unsigned short old;
	unsigned long flags;

	ctrl = &swap_cgroup_ctrl[type];

	mappage = ctrl->map[idx];
	sc = page_address(mappage);
	sc += pos;
	spin_lock_irqsave(&ctrl->lock, flags);
	old = sc->id;
	sc->id = id;
	spin_unlock_irqrestore(&ctrl->lock, flags);

	return old;
}

/**
 * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
 * @ent: swap entry to be looked up.
 *
 * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
 */
unsigned short lookup_swap_cgroup(swp_entry_t ent)
{
	int type = swp_type(ent);
	unsigned long offset = swp_offset(ent);
	unsigned long idx = offset / SC_PER_PAGE;
	unsigned long pos = offset & SC_POS_MASK;
	struct swap_cgroup_ctrl *ctrl;
	struct page *mappage;
	struct swap_cgroup *sc;
	unsigned short ret;

	ctrl = &swap_cgroup_ctrl[type];
	mappage = ctrl->map[idx];
	sc = page_address(mappage);
	sc += pos;
	ret = sc->id;
	return ret;
}

int swap_cgroup_swapon(int type, unsigned long max_pages)
{
	void *array;
	unsigned long array_size;
	unsigned long length;
	struct swap_cgroup_ctrl *ctrl;

	if (!do_swap_account)
		return 0;

	length = ((max_pages/SC_PER_PAGE) + 1);
	array_size = length * sizeof(void *);

	array = vmalloc(array_size);
	if (!array)
		goto nomem;

	memset(array, 0, array_size);
	ctrl = &swap_cgroup_ctrl[type];
	mutex_lock(&swap_cgroup_mutex);
	ctrl->length = length;
	ctrl->map = array;
	spin_lock_init(&ctrl->lock);
	if (swap_cgroup_prepare(type)) {
		/* memory shortage */
		ctrl->map = NULL;
		ctrl->length = 0;
		vfree(array);
		mutex_unlock(&swap_cgroup_mutex);
		goto nomem;
	}
	mutex_unlock(&swap_cgroup_mutex);

	return 0;
nomem:
	printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
	printk(KERN_INFO
		"swap_cgroup can be disabled by noswapaccount boot option\n");
	return -ENOMEM;
}

void swap_cgroup_swapoff(int type)
{
	int i;
	struct swap_cgroup_ctrl *ctrl;

	if (!do_swap_account)
		return;

	mutex_lock(&swap_cgroup_mutex);
	ctrl = &swap_cgroup_ctrl[type];
	if (ctrl->map) {
		for (i = 0; i < ctrl->length; i++) {
			struct page *page = ctrl->map[i];
			if (page)
				__free_page(page);
		}
		vfree(ctrl->map);
		ctrl->map = NULL;
		ctrl->length = 0;
	}
	mutex_unlock(&swap_cgroup_mutex);
}

#endif
Commit	Line	Data
52d4b9ac KH	1	#include <linux/mm.h>
	2	#include <linux/mmzone.h>
	3	#include <linux/bootmem.h>
	4	#include <linux/bit_spinlock.h>
	5	#include <linux/page_cgroup.h>
	6	#include <linux/hash.h>
94b6da5a	7	#include <linux/slab.h>
52d4b9ac	8	#include <linux/memory.h>
4c821042	9	#include <linux/vmalloc.h>
94b6da5a	10	#include <linux/cgroup.h>
27a7faa0	11	#include <linux/swapops.h>
7952f988	12	#include <linux/kmemleak.h>
52d4b9ac	13
6b3ae58e	14	static void __meminit init_page_cgroup(struct page_cgroup *pc, unsigned long id)
52d4b9ac KH	15	{
52d4b9ac KH	16	pc->flags = 0;
6b3ae58e	17	set_page_cgroup_array_id(pc, id);
52d4b9ac	18	pc->mem_cgroup = NULL;
08e552c6	19	INIT_LIST_HEAD(&pc->lru);
52d4b9ac KH	20	}
	21	static unsigned long total_usage;
	22
	23	#if !defined(CONFIG_SPARSEMEM)
	24
	25
31168481	26	void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
52d4b9ac KH	27	{
	28	pgdat->node_page_cgroup = NULL;
	29	}
	30
	31	struct page_cgroup lookup_page_cgroup(struct page page)
	32	{
	33	unsigned long pfn = page_to_pfn(page);
	34	unsigned long offset;
	35	struct page_cgroup *base;
	36
	37	base = NODE_DATA(page_to_nid(page))->node_page_cgroup;
	38	if (unlikely(!base))
	39	return NULL;
	40
	41	offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn;
	42	return base + offset;
	43	}
	44
6b3ae58e JW	45	struct page lookup_cgroup_page(struct page_cgroup pc)
	46	{
	47	unsigned long pfn;
	48	struct page *page;
	49	pg_data_t *pgdat;
	50
	51	pgdat = NODE_DATA(page_cgroup_array_id(pc));
	52	pfn = pc - pgdat->node_page_cgroup + pgdat->node_start_pfn;
	53	page = pfn_to_page(pfn);
	54	VM_BUG_ON(pc != lookup_page_cgroup(page));
	55	return page;
	56	}
	57
52d4b9ac KH	58	static int __init alloc_node_page_cgroup(int nid)
	59	{
	60	struct page_cgroup base, pc;
	61	unsigned long table_size;
	62	unsigned long start_pfn, nr_pages, index;
	63
	64	start_pfn = NODE_DATA(nid)->node_start_pfn;
	65	nr_pages = NODE_DATA(nid)->node_spanned_pages;
	66
653d22c0 KH	67	if (!nr_pages)
	68	return 0;
	69
52d4b9ac	70	table_size = sizeof(struct page_cgroup) * nr_pages;
ca371c0d KH	71
	72	base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
	73	table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
	74	if (!base)
52d4b9ac KH	75	return -ENOMEM;
	76	for (index = 0; index < nr_pages; index++) {
	77	pc = base + index;
6b3ae58e	78	init_page_cgroup(pc, nid);
52d4b9ac KH	79	}
	80	NODE_DATA(nid)->node_page_cgroup = base;
	81	total_usage += table_size;
	82	return 0;
	83	}
	84
ca371c0d	85	void __init page_cgroup_init_flatmem(void)
52d4b9ac KH	86	{
	87
	88	int nid, fail;
	89
f8d66542	90	if (mem_cgroup_disabled())
94b6da5a KH	91	return;
94b6da5a KH	92
52d4b9ac KH	93	for_each_online_node(nid) {
	94	fail = alloc_node_page_cgroup(nid);
	95	if (fail)
	96	goto fail;
	97	}
	98	printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
8ca739e3 RD	99	printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
8ca739e3 RD	100	" don't want memory cgroups\n");
52d4b9ac KH	101	return;
52d4b9ac KH	102	fail:
8ca739e3 RD	103	printk(KERN_CRIT "allocation of page_cgroup failed.\n");
8ca739e3 RD	104	printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
52d4b9ac KH	105	panic("Out of memory");
	106	}
	107
	108	#else /* CONFIG_FLAT_NODE_MEM_MAP */
	109
	110	struct page_cgroup lookup_page_cgroup(struct page page)
	111	{
	112	unsigned long pfn = page_to_pfn(page);
	113	struct mem_section *section = __pfn_to_section(pfn);
	114
d69b042f BS	115	if (!section->page_cgroup)
d69b042f BS	116	return NULL;
52d4b9ac KH	117	return section->page_cgroup + pfn;
	118	}
	119
6b3ae58e JW	120	struct page lookup_cgroup_page(struct page_cgroup pc)
	121	{
	122	struct mem_section *section;
	123	struct page *page;
	124	unsigned long nr;
	125
	126	nr = page_cgroup_array_id(pc);
	127	section = __nr_to_section(nr);
	128	page = pfn_to_page(pc - section->page_cgroup);
	129	VM_BUG_ON(pc != lookup_page_cgroup(page));
	130	return page;
	131	}
	132
31168481	133	/* __alloc_bootmem...() is protected by !slab_available() */
feb16694	134	static int __init_refok init_section_page_cgroup(unsigned long pfn)
52d4b9ac	135	{
52d4b9ac	136	struct page_cgroup base, pc;
6b3ae58e	137	struct mem_section *section;
52d4b9ac	138	unsigned long table_size;
6b3ae58e	139	unsigned long nr;
52d4b9ac KH	140	int nid, index;
52d4b9ac KH	141
6b3ae58e JW	142	nr = pfn_to_section_nr(pfn);
	143	section = __nr_to_section(nr);
	144
	145	if (section->page_cgroup)
	146	return 0;
	147
	148	nid = page_to_nid(pfn_to_page(pfn));
	149	table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
	150	VM_BUG_ON(!slab_is_available());
	151	if (node_state(nid, N_HIGH_MEMORY)) {
	152	base = kmalloc_node(table_size,
	153	GFP_KERNEL \| __GFP_NOWARN, nid);
	154	if (!base)
	155	base = vmalloc_node(table_size, nid);
dc19f9db	156	} else {
6b3ae58e JW	157	base = kmalloc(table_size, GFP_KERNEL \| __GFP_NOWARN);
	158	if (!base)
	159	base = vmalloc(table_size);
94b6da5a	160	}
6b3ae58e JW	161	/*
	162	* The value stored in section->page_cgroup is (base - pfn)
	163	* and it does not point to the memory block allocated above,
	164	* causing kmemleak false positives.
	165	*/
	166	kmemleak_not_leak(base);
52d4b9ac KH	167
	168	if (!base) {
	169	printk(KERN_ERR "page cgroup allocation failure\n");
	170	return -ENOMEM;
	171	}
	172
	173	for (index = 0; index < PAGES_PER_SECTION; index++) {
	174	pc = base + index;
6b3ae58e	175	init_page_cgroup(pc, nr);
52d4b9ac KH	176	}
52d4b9ac KH	177
52d4b9ac KH	178	section->page_cgroup = base - pfn;
	179	total_usage += table_size;
	180	return 0;
	181	}
	182	#ifdef CONFIG_MEMORY_HOTPLUG
	183	void __free_page_cgroup(unsigned long pfn)
	184	{
	185	struct mem_section *ms;
	186	struct page_cgroup *base;
	187
	188	ms = __pfn_to_section(pfn);
	189	if (!ms \|\| !ms->page_cgroup)
	190	return;
	191	base = ms->page_cgroup + pfn;
94b6da5a	192	if (is_vmalloc_addr(base)) {
52d4b9ac	193	vfree(base);
94b6da5a KH	194	ms->page_cgroup = NULL;
	195	} else {
	196	struct page *page = virt_to_page(base);
	197	if (!PageReserved(page)) { /* Is bootmem ? */
	198	kfree(base);
	199	ms->page_cgroup = NULL;
	200	}
	201	}
52d4b9ac KH	202	}
52d4b9ac KH	203
31168481	204	int __meminit online_page_cgroup(unsigned long start_pfn,
52d4b9ac KH	205	unsigned long nr_pages,
	206	int nid)
	207	{
	208	unsigned long start, end, pfn;
	209	int fail = 0;
	210
33c5d3d6	211	start = start_pfn & ~(PAGES_PER_SECTION - 1);
52d4b9ac KH	212	end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
	213
	214	for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
	215	if (!pfn_present(pfn))
	216	continue;
	217	fail = init_section_page_cgroup(pfn);
	218	}
	219	if (!fail)
	220	return 0;
	221
	222	/* rollback */
	223	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
	224	__free_page_cgroup(pfn);
	225
	226	return -ENOMEM;
	227	}
	228
31168481	229	int __meminit offline_page_cgroup(unsigned long start_pfn,
52d4b9ac KH	230	unsigned long nr_pages, int nid)
	231	{
	232	unsigned long start, end, pfn;
	233
33c5d3d6	234	start = start_pfn & ~(PAGES_PER_SECTION - 1);
52d4b9ac KH	235	end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
	236
	237	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
	238	__free_page_cgroup(pfn);
	239	return 0;
	240
	241	}
	242
31168481	243	static int __meminit page_cgroup_callback(struct notifier_block *self,
52d4b9ac KH	244	unsigned long action, void *arg)
	245	{
	246	struct memory_notify *mn = arg;
	247	int ret = 0;
	248	switch (action) {
	249	case MEM_GOING_ONLINE:
	250	ret = online_page_cgroup(mn->start_pfn,
	251	mn->nr_pages, mn->status_change_nid);
	252	break;
52d4b9ac KH	253	case MEM_OFFLINE:
	254	offline_page_cgroup(mn->start_pfn,
	255	mn->nr_pages, mn->status_change_nid);
	256	break;
dc19f9db	257	case MEM_CANCEL_ONLINE:
52d4b9ac KH	258	case MEM_GOING_OFFLINE:
	259	break;
	260	case MEM_ONLINE:
	261	case MEM_CANCEL_OFFLINE:
	262	break;
	263	}
dc19f9db	264
5fda1bd5	265	return notifier_from_errno(ret);
52d4b9ac KH	266	}
	267
	268	#endif
	269
	270	void __init page_cgroup_init(void)
	271	{
	272	unsigned long pfn;
	273	int fail = 0;
	274
f8d66542	275	if (mem_cgroup_disabled())
94b6da5a KH	276	return;
94b6da5a KH	277
52d4b9ac KH	278	for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
	279	if (!pfn_present(pfn))
	280	continue;
	281	fail = init_section_page_cgroup(pfn);
	282	}
	283	if (fail) {
8ca739e3	284	printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
52d4b9ac KH	285	panic("Out of memory");
	286	} else {
	287	hotplug_memory_notifier(page_cgroup_callback, 0);
	288	}
	289	printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
8ca739e3 RD	290	printk(KERN_INFO "please try 'cgroup_disable=memory' option if you don't"
8ca739e3 RD	291	" want memory cgroups\n");
52d4b9ac KH	292	}
52d4b9ac KH	293
31168481	294	void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
52d4b9ac KH	295	{
	296	return;
	297	}
	298
	299	#endif
27a7faa0 KH	300
	301
	302	#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
	303
	304	static DEFINE_MUTEX(swap_cgroup_mutex);
	305	struct swap_cgroup_ctrl {
	306	struct page **map;
	307	unsigned long length;
e9e58a4e	308	spinlock_t lock;
27a7faa0 KH	309	};
	310
	311	struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
	312
27a7faa0	313	struct swap_cgroup {
a3b2d692	314	unsigned short id;
27a7faa0 KH	315	};
	316	#define SC_PER_PAGE (PAGE_SIZE/sizeof(struct swap_cgroup))
	317	#define SC_POS_MASK (SC_PER_PAGE - 1)
	318
	319	/*
	320	* SwapCgroup implements "lookup" and "exchange" operations.
	321	* In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
	322	* against SwapCache. At swap_free(), this is accessed directly from swap.
	323	*
	324	* This means,
	325	* - we have no race in "exchange" when we're accessed via SwapCache because
	326	* SwapCache(and its swp_entry) is under lock.
	327	* - When called via swap_free(), there is no user of this entry and no race.
	328	* Then, we don't need lock around "exchange".
	329	*
	330	* TODO: we can push these buffers out to HIGHMEM.
	331	*/
	332
	333	/*
	334	* allocate buffer for swap_cgroup.
	335	*/
	336	static int swap_cgroup_prepare(int type)
	337	{
	338	struct page *page;
	339	struct swap_cgroup_ctrl *ctrl;
	340	unsigned long idx, max;
	341
27a7faa0 KH	342	ctrl = &swap_cgroup_ctrl[type];
	343
	344	for (idx = 0; idx < ctrl->length; idx++) {
	345	page = alloc_page(GFP_KERNEL \| __GFP_ZERO);
	346	if (!page)
	347	goto not_enough_page;
	348	ctrl->map[idx] = page;
	349	}
	350	return 0;
	351	not_enough_page:
	352	max = idx;
	353	for (idx = 0; idx < max; idx++)
	354	__free_page(ctrl->map[idx]);
	355
	356	return -ENOMEM;
	357	}
	358
02491447 DN	359	/**
	360	* swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
	361	* @end: swap entry to be cmpxchged
	362	* @old: old id
	363	* @new: new id
	364	*
	365	* Returns old id at success, 0 at failure.
	366	* (There is no mem_cgroup useing 0 as its id)
	367	*/
	368	unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
	369	unsigned short old, unsigned short new)
	370	{
	371	int type = swp_type(ent);
	372	unsigned long offset = swp_offset(ent);
	373	unsigned long idx = offset / SC_PER_PAGE;
	374	unsigned long pos = offset & SC_POS_MASK;
	375	struct swap_cgroup_ctrl *ctrl;
	376	struct page *mappage;
	377	struct swap_cgroup *sc;
e9e58a4e KH	378	unsigned long flags;
e9e58a4e KH	379	unsigned short retval;
02491447 DN	380
	381	ctrl = &swap_cgroup_ctrl[type];
	382
	383	mappage = ctrl->map[idx];
	384	sc = page_address(mappage);
	385	sc += pos;
e9e58a4e KH	386	spin_lock_irqsave(&ctrl->lock, flags);
	387	retval = sc->id;
	388	if (retval == old)
	389	sc->id = new;
02491447	390	else
e9e58a4e KH	391	retval = 0;
	392	spin_unlock_irqrestore(&ctrl->lock, flags);
	393	return retval;
02491447 DN	394	}
02491447 DN	395
27a7faa0 KH	396	/**
	397	* swap_cgroup_record - record mem_cgroup for this swp_entry.
	398	* @ent: swap entry to be recorded into
	399	* @mem: mem_cgroup to be recorded
	400	*
a3b2d692 KH	401	* Returns old value at success, 0 at failure.
a3b2d692 KH	402	* (Of course, old value can be 0.)
27a7faa0	403	*/
a3b2d692	404	unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
27a7faa0 KH	405	{
	406	int type = swp_type(ent);
	407	unsigned long offset = swp_offset(ent);
	408	unsigned long idx = offset / SC_PER_PAGE;
	409	unsigned long pos = offset & SC_POS_MASK;
	410	struct swap_cgroup_ctrl *ctrl;
	411	struct page *mappage;
	412	struct swap_cgroup *sc;
a3b2d692	413	unsigned short old;
e9e58a4e	414	unsigned long flags;
27a7faa0	415
27a7faa0 KH	416	ctrl = &swap_cgroup_ctrl[type];
	417
	418	mappage = ctrl->map[idx];
	419	sc = page_address(mappage);
	420	sc += pos;
e9e58a4e KH	421	spin_lock_irqsave(&ctrl->lock, flags);
	422	old = sc->id;
	423	sc->id = id;
	424	spin_unlock_irqrestore(&ctrl->lock, flags);
27a7faa0 KH	425
	426	return old;
	427	}
	428
	429	/**
	430	* lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
	431	* @ent: swap entry to be looked up.
	432	*
a3b2d692	433	* Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
27a7faa0	434	*/
a3b2d692	435	unsigned short lookup_swap_cgroup(swp_entry_t ent)
27a7faa0 KH	436	{
	437	int type = swp_type(ent);
	438	unsigned long offset = swp_offset(ent);
	439	unsigned long idx = offset / SC_PER_PAGE;
	440	unsigned long pos = offset & SC_POS_MASK;
	441	struct swap_cgroup_ctrl *ctrl;
	442	struct page *mappage;
	443	struct swap_cgroup *sc;
a3b2d692	444	unsigned short ret;
27a7faa0	445
27a7faa0 KH	446	ctrl = &swap_cgroup_ctrl[type];
	447	mappage = ctrl->map[idx];
	448	sc = page_address(mappage);
	449	sc += pos;
a3b2d692	450	ret = sc->id;
27a7faa0 KH	451	return ret;
	452	}
	453
	454	int swap_cgroup_swapon(int type, unsigned long max_pages)
	455	{
	456	void *array;
	457	unsigned long array_size;
	458	unsigned long length;
	459	struct swap_cgroup_ctrl *ctrl;
	460
	461	if (!do_swap_account)
	462	return 0;
	463
	464	length = ((max_pages/SC_PER_PAGE) + 1);
	465	array_size = length * sizeof(void *);
	466
	467	array = vmalloc(array_size);
	468	if (!array)
	469	goto nomem;
	470
	471	memset(array, 0, array_size);
	472	ctrl = &swap_cgroup_ctrl[type];
	473	mutex_lock(&swap_cgroup_mutex);
	474	ctrl->length = length;
	475	ctrl->map = array;
e9e58a4e	476	spin_lock_init(&ctrl->lock);
27a7faa0 KH	477	if (swap_cgroup_prepare(type)) {
	478	/* memory shortage */
	479	ctrl->map = NULL;
	480	ctrl->length = 0;
	481	vfree(array);
	482	mutex_unlock(&swap_cgroup_mutex);
	483	goto nomem;
	484	}
	485	mutex_unlock(&swap_cgroup_mutex);
	486
27a7faa0 KH	487	return 0;
	488	nomem:
	489	printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
	490	printk(KERN_INFO
	491	"swap_cgroup can be disabled by noswapaccount boot option\n");
	492	return -ENOMEM;
	493	}
	494
	495	void swap_cgroup_swapoff(int type)
	496	{
	497	int i;
	498	struct swap_cgroup_ctrl *ctrl;
	499
	500	if (!do_swap_account)
	501	return;
	502
	503	mutex_lock(&swap_cgroup_mutex);
	504	ctrl = &swap_cgroup_ctrl[type];
	505	if (ctrl->map) {
	506	for (i = 0; i < ctrl->length; i++) {
	507	struct page *page = ctrl->map[i];
	508	if (page)
	509	__free_page(page);
	510	}
	511	vfree(ctrl->map);
	512	ctrl->map = NULL;
	513	ctrl->length = 0;
	514	}
	515	mutex_unlock(&swap_cgroup_mutex);
	516	}
	517
	518	#endif