[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 pfn)
{
	pc->flags = 0;
	pc->mem_cgroup = NULL;
	pc->page = pfn_to_page(pfn);
	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;
}

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, start_pfn + index);
	}
	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;
}

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

	if (!section->page_cgroup) {
		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);
	} else {
		/*
 		 * We don't have to allocate page_cgroup again, but
		 * address of memmap may be changed. So, we have to initialize
		 * again.
		 */
		base = section->page_cgroup + pfn;
		table_size = 0;
		/* check address of memmap is changed or not. */
		if (base->page == pfn_to_page(pfn))
			return 0;
	}

	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->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 KH	13
	14	static void __meminit
	15	__init_page_cgroup(struct page_cgroup *pc, unsigned long pfn)
	16	{
	17	pc->flags = 0;
	18	pc->mem_cgroup = NULL;
	19	pc->page = pfn_to_page(pfn);
08e552c6	20	INIT_LIST_HEAD(&pc->lru);
52d4b9ac KH	21	}
	22	static unsigned long total_usage;
	23
	24	#if !defined(CONFIG_SPARSEMEM)
	25
	26
31168481	27	void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
52d4b9ac KH	28	{
	29	pgdat->node_page_cgroup = NULL;
	30	}
	31
	32	struct page_cgroup lookup_page_cgroup(struct page page)
	33	{
	34	unsigned long pfn = page_to_pfn(page);
	35	unsigned long offset;
	36	struct page_cgroup *base;
	37
	38	base = NODE_DATA(page_to_nid(page))->node_page_cgroup;
	39	if (unlikely(!base))
	40	return NULL;
	41
	42	offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn;
	43	return base + offset;
	44	}
	45
	46	static int __init alloc_node_page_cgroup(int nid)
	47	{
	48	struct page_cgroup base, pc;
	49	unsigned long table_size;
	50	unsigned long start_pfn, nr_pages, index;
	51
	52	start_pfn = NODE_DATA(nid)->node_start_pfn;
	53	nr_pages = NODE_DATA(nid)->node_spanned_pages;
	54
653d22c0 KH	55	if (!nr_pages)
	56	return 0;
	57
52d4b9ac	58	table_size = sizeof(struct page_cgroup) * nr_pages;
ca371c0d KH	59
	60	base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
	61	table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
	62	if (!base)
52d4b9ac KH	63	return -ENOMEM;
	64	for (index = 0; index < nr_pages; index++) {
	65	pc = base + index;
	66	__init_page_cgroup(pc, start_pfn + index);
	67	}
	68	NODE_DATA(nid)->node_page_cgroup = base;
	69	total_usage += table_size;
	70	return 0;
	71	}
	72
ca371c0d	73	void __init page_cgroup_init_flatmem(void)
52d4b9ac KH	74	{
	75
	76	int nid, fail;
	77
f8d66542	78	if (mem_cgroup_disabled())
94b6da5a KH	79	return;
94b6da5a KH	80
52d4b9ac KH	81	for_each_online_node(nid) {
	82	fail = alloc_node_page_cgroup(nid);
	83	if (fail)
	84	goto fail;
	85	}
	86	printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
8ca739e3 RD	87	printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
8ca739e3 RD	88	" don't want memory cgroups\n");
52d4b9ac KH	89	return;
52d4b9ac KH	90	fail:
8ca739e3 RD	91	printk(KERN_CRIT "allocation of page_cgroup failed.\n");
8ca739e3 RD	92	printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
52d4b9ac KH	93	panic("Out of memory");
	94	}
	95
	96	#else /* CONFIG_FLAT_NODE_MEM_MAP */
	97
	98	struct page_cgroup lookup_page_cgroup(struct page page)
	99	{
	100	unsigned long pfn = page_to_pfn(page);
	101	struct mem_section *section = __pfn_to_section(pfn);
	102
d69b042f BS	103	if (!section->page_cgroup)
d69b042f BS	104	return NULL;
52d4b9ac KH	105	return section->page_cgroup + pfn;
	106	}
	107
31168481	108	/* __alloc_bootmem...() is protected by !slab_available() */
feb16694	109	static int __init_refok init_section_page_cgroup(unsigned long pfn)
52d4b9ac	110	{
0753b0ef	111	struct mem_section *section = __pfn_to_section(pfn);
52d4b9ac KH	112	struct page_cgroup base, pc;
	113	unsigned long table_size;
	114	int nid, index;
	115
dc19f9db KH	116	if (!section->page_cgroup) {
	117	nid = page_to_nid(pfn_to_page(pfn));
	118	table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
ca371c0d	119	VM_BUG_ON(!slab_is_available());
f52407ce SL	120	if (node_state(nid, N_HIGH_MEMORY)) {
f52407ce SL	121	base = kmalloc_node(table_size,
ca371c0d	122	GFP_KERNEL \| __GFP_NOWARN, nid);
f52407ce SL	123	if (!base)
	124	base = vmalloc_node(table_size, nid);
	125	} else {
	126	base = kmalloc(table_size, GFP_KERNEL \| __GFP_NOWARN);
	127	if (!base)
	128	base = vmalloc(table_size);
	129	}
7952f988 CM	130	/*
	131	* The value stored in section->page_cgroup is (base - pfn)
	132	* and it does not point to the memory block allocated above,
	133	* causing kmemleak false positives.
	134	*/
	135	kmemleak_not_leak(base);
dc19f9db KH	136	} else {
	137	/*
	138	* We don't have to allocate page_cgroup again, but
	139	* address of memmap may be changed. So, we have to initialize
	140	* again.
	141	*/
	142	base = section->page_cgroup + pfn;
	143	table_size = 0;
	144	/* check address of memmap is changed or not. */
	145	if (base->page == pfn_to_page(pfn))
	146	return 0;
94b6da5a	147	}
52d4b9ac KH	148
	149	if (!base) {
	150	printk(KERN_ERR "page cgroup allocation failure\n");
	151	return -ENOMEM;
	152	}
	153
	154	for (index = 0; index < PAGES_PER_SECTION; index++) {
	155	pc = base + index;
	156	__init_page_cgroup(pc, pfn + index);
	157	}
	158
52d4b9ac KH	159	section->page_cgroup = base - pfn;
	160	total_usage += table_size;
	161	return 0;
	162	}
	163	#ifdef CONFIG_MEMORY_HOTPLUG
	164	void __free_page_cgroup(unsigned long pfn)
	165	{
	166	struct mem_section *ms;
	167	struct page_cgroup *base;
	168
	169	ms = __pfn_to_section(pfn);
	170	if (!ms \|\| !ms->page_cgroup)
	171	return;
	172	base = ms->page_cgroup + pfn;
94b6da5a	173	if (is_vmalloc_addr(base)) {
52d4b9ac	174	vfree(base);
94b6da5a KH	175	ms->page_cgroup = NULL;
	176	} else {
	177	struct page *page = virt_to_page(base);
	178	if (!PageReserved(page)) { /* Is bootmem ? */
	179	kfree(base);
	180	ms->page_cgroup = NULL;
	181	}
	182	}
52d4b9ac KH	183	}
52d4b9ac KH	184
31168481	185	int __meminit online_page_cgroup(unsigned long start_pfn,
52d4b9ac KH	186	unsigned long nr_pages,
	187	int nid)
	188	{
	189	unsigned long start, end, pfn;
	190	int fail = 0;
	191
33c5d3d6	192	start = start_pfn & ~(PAGES_PER_SECTION - 1);
52d4b9ac KH	193	end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
	194
	195	for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
	196	if (!pfn_present(pfn))
	197	continue;
	198	fail = init_section_page_cgroup(pfn);
	199	}
	200	if (!fail)
	201	return 0;
	202
	203	/* rollback */
	204	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
	205	__free_page_cgroup(pfn);
	206
	207	return -ENOMEM;
	208	}
	209
31168481	210	int __meminit offline_page_cgroup(unsigned long start_pfn,
52d4b9ac KH	211	unsigned long nr_pages, int nid)
	212	{
	213	unsigned long start, end, pfn;
	214
33c5d3d6	215	start = start_pfn & ~(PAGES_PER_SECTION - 1);
52d4b9ac KH	216	end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
	217
	218	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
	219	__free_page_cgroup(pfn);
	220	return 0;
	221
	222	}
	223
31168481	224	static int __meminit page_cgroup_callback(struct notifier_block *self,
52d4b9ac KH	225	unsigned long action, void *arg)
	226	{
	227	struct memory_notify *mn = arg;
	228	int ret = 0;
	229	switch (action) {
	230	case MEM_GOING_ONLINE:
	231	ret = online_page_cgroup(mn->start_pfn,
	232	mn->nr_pages, mn->status_change_nid);
	233	break;
52d4b9ac KH	234	case MEM_OFFLINE:
	235	offline_page_cgroup(mn->start_pfn,
	236	mn->nr_pages, mn->status_change_nid);
	237	break;
dc19f9db	238	case MEM_CANCEL_ONLINE:
52d4b9ac KH	239	case MEM_GOING_OFFLINE:
	240	break;
	241	case MEM_ONLINE:
	242	case MEM_CANCEL_OFFLINE:
	243	break;
	244	}
dc19f9db	245
5fda1bd5	246	return notifier_from_errno(ret);
52d4b9ac KH	247	}
	248
	249	#endif
	250
	251	void __init page_cgroup_init(void)
	252	{
	253	unsigned long pfn;
	254	int fail = 0;
	255
f8d66542	256	if (mem_cgroup_disabled())
94b6da5a KH	257	return;
94b6da5a KH	258
52d4b9ac KH	259	for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
	260	if (!pfn_present(pfn))
	261	continue;
	262	fail = init_section_page_cgroup(pfn);
	263	}
	264	if (fail) {
8ca739e3	265	printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
52d4b9ac KH	266	panic("Out of memory");
	267	} else {
	268	hotplug_memory_notifier(page_cgroup_callback, 0);
	269	}
	270	printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
8ca739e3 RD	271	printk(KERN_INFO "please try 'cgroup_disable=memory' option if you don't"
8ca739e3 RD	272	" want memory cgroups\n");
52d4b9ac KH	273	}
52d4b9ac KH	274
31168481	275	void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
52d4b9ac KH	276	{
	277	return;
	278	}
	279
	280	#endif
27a7faa0 KH	281
	282
	283	#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
	284
	285	static DEFINE_MUTEX(swap_cgroup_mutex);
	286	struct swap_cgroup_ctrl {
	287	struct page **map;
	288	unsigned long length;
e9e58a4e	289	spinlock_t lock;
27a7faa0 KH	290	};
	291
	292	struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
	293
27a7faa0	294	struct swap_cgroup {
a3b2d692	295	unsigned short id;
27a7faa0 KH	296	};
	297	#define SC_PER_PAGE (PAGE_SIZE/sizeof(struct swap_cgroup))
	298	#define SC_POS_MASK (SC_PER_PAGE - 1)
	299
	300	/*
	301	* SwapCgroup implements "lookup" and "exchange" operations.
	302	* In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
	303	* against SwapCache. At swap_free(), this is accessed directly from swap.
	304	*
	305	* This means,
	306	* - we have no race in "exchange" when we're accessed via SwapCache because
	307	* SwapCache(and its swp_entry) is under lock.
	308	* - When called via swap_free(), there is no user of this entry and no race.
	309	* Then, we don't need lock around "exchange".
	310	*
	311	* TODO: we can push these buffers out to HIGHMEM.
	312	*/
	313
	314	/*
	315	* allocate buffer for swap_cgroup.
	316	*/
	317	static int swap_cgroup_prepare(int type)
	318	{
	319	struct page *page;
	320	struct swap_cgroup_ctrl *ctrl;
	321	unsigned long idx, max;
	322
27a7faa0 KH	323	ctrl = &swap_cgroup_ctrl[type];
	324
	325	for (idx = 0; idx < ctrl->length; idx++) {
	326	page = alloc_page(GFP_KERNEL \| __GFP_ZERO);
	327	if (!page)
	328	goto not_enough_page;
	329	ctrl->map[idx] = page;
	330	}
	331	return 0;
	332	not_enough_page:
	333	max = idx;
	334	for (idx = 0; idx < max; idx++)
	335	__free_page(ctrl->map[idx]);
	336
	337	return -ENOMEM;
	338	}
	339
02491447 DN	340	/**
	341	* swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
	342	* @end: swap entry to be cmpxchged
	343	* @old: old id
	344	* @new: new id
	345	*
	346	* Returns old id at success, 0 at failure.
	347	* (There is no mem_cgroup useing 0 as its id)
	348	*/
	349	unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
	350	unsigned short old, unsigned short new)
	351	{
	352	int type = swp_type(ent);
	353	unsigned long offset = swp_offset(ent);
	354	unsigned long idx = offset / SC_PER_PAGE;
	355	unsigned long pos = offset & SC_POS_MASK;
	356	struct swap_cgroup_ctrl *ctrl;
	357	struct page *mappage;
	358	struct swap_cgroup *sc;
e9e58a4e KH	359	unsigned long flags;
e9e58a4e KH	360	unsigned short retval;
02491447 DN	361
	362	ctrl = &swap_cgroup_ctrl[type];
	363
	364	mappage = ctrl->map[idx];
	365	sc = page_address(mappage);
	366	sc += pos;
e9e58a4e KH	367	spin_lock_irqsave(&ctrl->lock, flags);
	368	retval = sc->id;
	369	if (retval == old)
	370	sc->id = new;
02491447	371	else
e9e58a4e KH	372	retval = 0;
	373	spin_unlock_irqrestore(&ctrl->lock, flags);
	374	return retval;
02491447 DN	375	}
02491447 DN	376
27a7faa0 KH	377	/**
	378	* swap_cgroup_record - record mem_cgroup for this swp_entry.
	379	* @ent: swap entry to be recorded into
	380	* @mem: mem_cgroup to be recorded
	381	*
a3b2d692 KH	382	* Returns old value at success, 0 at failure.
a3b2d692 KH	383	* (Of course, old value can be 0.)
27a7faa0	384	*/
a3b2d692	385	unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
27a7faa0 KH	386	{
	387	int type = swp_type(ent);
	388	unsigned long offset = swp_offset(ent);
	389	unsigned long idx = offset / SC_PER_PAGE;
	390	unsigned long pos = offset & SC_POS_MASK;
	391	struct swap_cgroup_ctrl *ctrl;
	392	struct page *mappage;
	393	struct swap_cgroup *sc;
a3b2d692	394	unsigned short old;
e9e58a4e	395	unsigned long flags;
27a7faa0	396
27a7faa0 KH	397	ctrl = &swap_cgroup_ctrl[type];
	398
	399	mappage = ctrl->map[idx];
	400	sc = page_address(mappage);
	401	sc += pos;
e9e58a4e KH	402	spin_lock_irqsave(&ctrl->lock, flags);
	403	old = sc->id;
	404	sc->id = id;
	405	spin_unlock_irqrestore(&ctrl->lock, flags);
27a7faa0 KH	406
	407	return old;
	408	}
	409
	410	/**
	411	* lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
	412	* @ent: swap entry to be looked up.
	413	*
a3b2d692	414	* Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
27a7faa0	415	*/
a3b2d692	416	unsigned short lookup_swap_cgroup(swp_entry_t ent)
27a7faa0 KH	417	{
	418	int type = swp_type(ent);
	419	unsigned long offset = swp_offset(ent);
	420	unsigned long idx = offset / SC_PER_PAGE;
	421	unsigned long pos = offset & SC_POS_MASK;
	422	struct swap_cgroup_ctrl *ctrl;
	423	struct page *mappage;
	424	struct swap_cgroup *sc;
a3b2d692	425	unsigned short ret;
27a7faa0	426
27a7faa0 KH	427	ctrl = &swap_cgroup_ctrl[type];
	428	mappage = ctrl->map[idx];
	429	sc = page_address(mappage);
	430	sc += pos;
a3b2d692	431	ret = sc->id;
27a7faa0 KH	432	return ret;
	433	}
	434
	435	int swap_cgroup_swapon(int type, unsigned long max_pages)
	436	{
	437	void *array;
	438	unsigned long array_size;
	439	unsigned long length;
	440	struct swap_cgroup_ctrl *ctrl;
	441
	442	if (!do_swap_account)
	443	return 0;
	444
	445	length = ((max_pages/SC_PER_PAGE) + 1);
	446	array_size = length * sizeof(void *);
	447
	448	array = vmalloc(array_size);
	449	if (!array)
	450	goto nomem;
	451
	452	memset(array, 0, array_size);
	453	ctrl = &swap_cgroup_ctrl[type];
	454	mutex_lock(&swap_cgroup_mutex);
	455	ctrl->length = length;
	456	ctrl->map = array;
e9e58a4e	457	spin_lock_init(&ctrl->lock);
27a7faa0 KH	458	if (swap_cgroup_prepare(type)) {
	459	/* memory shortage */
	460	ctrl->map = NULL;
	461	ctrl->length = 0;
	462	vfree(array);
	463	mutex_unlock(&swap_cgroup_mutex);
	464	goto nomem;
	465	}
	466	mutex_unlock(&swap_cgroup_mutex);
	467
27a7faa0 KH	468	return 0;
	469	nomem:
	470	printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
	471	printk(KERN_INFO
	472	"swap_cgroup can be disabled by noswapaccount boot option\n");
	473	return -ENOMEM;
	474	}
	475
	476	void swap_cgroup_swapoff(int type)
	477	{
	478	int i;
	479	struct swap_cgroup_ctrl *ctrl;
	480
	481	if (!do_swap_account)
	482	return;
	483
	484	mutex_lock(&swap_cgroup_mutex);
	485	ctrl = &swap_cgroup_ctrl[type];
	486	if (ctrl->map) {
	487	for (i = 0; i < ctrl->length; i++) {
	488	struct page *page = ctrl->map[i];
	489	if (page)
	490	__free_page(page);
	491	}
	492	vfree(ctrl->map);
	493	ctrl->map = NULL;
	494	ctrl->length = 0;
	495	}
	496	mutex_unlock(&swap_cgroup_mutex);
	497	}
	498
	499	#endif