[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 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;
#ifdef CONFIG_DEBUG_VM
	/*
	 * The sanity checks the page allocator does upon freeing a
	 * page can reach here before the page_cgroup arrays are
	 * allocated when feeding a range of pages to the allocator
	 * for the first time during bootup or memory hotplug.
	 */
	if (unlikely(!base))
		return NULL;
#endif
	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;
	unsigned long table_size;
	unsigned long nr_pages;

	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;
	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);
#ifdef CONFIG_DEBUG_VM
	/*
	 * The sanity checks the page allocator does upon freeing a
	 * page can reach here before the page_cgroup arrays are
	 * allocated when feeding a range of pages to the allocator
	 * for the first time during bootup or memory hotplug.
	 */
	if (!section->page_cgroup)
		return NULL;
#endif
	return section->page_cgroup + pfn;
}

static void *__meminit alloc_page_cgroup(size_t size, int nid)
{
	gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN;
	void *addr = NULL;

	addr = alloc_pages_exact_nid(nid, size, flags);
	if (addr) {
		kmemleak_alloc(addr, size, 1, flags);
		return addr;
	}

	if (node_state(nid, N_HIGH_MEMORY))
		addr = vzalloc_node(size, nid);
	else
		addr = vzalloc(size);

	return addr;
}

static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
{
	struct mem_section *section;
	struct page_cgroup *base;
	unsigned long table_size;

	section = __pfn_to_section(pfn);

	if (section->page_cgroup)
		return 0;

	table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
	base = alloc_page_cgroup(table_size, nid);

	/*
	 * 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;
	}

	/*
	 * The passed "pfn" may not be aligned to SECTION.  For the calculation
	 * we need to apply a mask.
	 */
	pfn &= PAGE_SECTION_MASK;
	section->page_cgroup = base - pfn;
	total_usage += table_size;
	return 0;
}
#ifdef CONFIG_MEMORY_HOTPLUG
static void free_page_cgroup(void *addr)
{
	if (is_vmalloc_addr(addr)) {
		vfree(addr);
	} else {
		struct page *page = virt_to_page(addr);
		size_t table_size =
			sizeof(struct page_cgroup) * PAGES_PER_SECTION;

		BUG_ON(PageReserved(page));
		free_pages_exact(addr, table_size);
	}
}

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;
	free_page_cgroup(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 = SECTION_ALIGN_DOWN(start_pfn);
	end = SECTION_ALIGN_UP(start_pfn + nr_pages);

	if (nid == -1) {
		/*
		 * In this case, "nid" already exists and contains valid memory.
		 * "start_pfn" passed to us is a pfn which is an arg for
		 * online__pages(), and start_pfn should exist.
		 */
		nid = pfn_to_nid(start_pfn);
		VM_BUG_ON(!node_state(nid, N_ONLINE));
	}

	for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
		if (!pfn_present(pfn))
			continue;
		fail = init_section_page_cgroup(pfn, nid);
	}
	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 = SECTION_ALIGN_DOWN(start_pfn);
	end = SECTION_ALIGN_UP(start_pfn + nr_pages);

	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:
		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;
	}

	return notifier_from_errno(ret);
}

#endif

void __init page_cgroup_init(void)
{
	unsigned long pfn;
	int nid;

	if (mem_cgroup_disabled())
		return;

	for_each_node_state(nid, N_MEMORY) {
		unsigned long start_pfn, end_pfn;

		start_pfn = node_start_pfn(nid);
		end_pfn = node_end_pfn(nid);
		/*
		 * start_pfn and end_pfn may not be aligned to SECTION and the
		 * page->flags of out of node pages are not initialized.  So we
		 * scan [start_pfn, the biggest section's pfn < end_pfn) here.
		 */
		for (pfn = start_pfn;
		     pfn < end_pfn;
                     pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) {

			if (!pfn_valid(pfn))
				continue;
			/*
			 * Nodes's pfns can be overlapping.
			 * We know some arch can have a nodes layout such as
			 * -------------pfn-------------->
			 * N0 | N1 | N2 | N0 | N1 | N2|....
			 */
			if (pfn_to_nid(pfn) != nid)
				continue;
			if (init_section_page_cgroup(pfn, nid))
				goto oom;
		}
	}
	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");
	return;
oom:
	printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
	panic("Out of memory");
}

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

#endif


#ifdef CONFIG_MEMCG_SWAP

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

static 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))

/*
 * 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;
}

static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
					struct swap_cgroup_ctrl **ctrlp)
{
	pgoff_t offset = swp_offset(ent);
	struct swap_cgroup_ctrl *ctrl;
	struct page *mappage;
	struct swap_cgroup *sc;

	ctrl = &swap_cgroup_ctrl[swp_type(ent)];
	if (ctrlp)
		*ctrlp = ctrl;

	mappage = ctrl->map[offset / SC_PER_PAGE];
	sc = page_address(mappage);
	return sc + offset % SC_PER_PAGE;
}

/**
 * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
 * @ent: swap entry to be cmpxchged
 * @old: old id
 * @new: new id
 *
 * Returns old id at success, 0 at failure.
 * (There is no mem_cgroup using 0 as its id)
 */
unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
					unsigned short old, unsigned short new)
{
	struct swap_cgroup_ctrl *ctrl;
	struct swap_cgroup *sc;
	unsigned long flags;
	unsigned short retval;

	sc = lookup_swap_cgroup(ent, &ctrl);

	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
 * @id: 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)
{
	struct swap_cgroup_ctrl *ctrl;
	struct swap_cgroup *sc;
	unsigned short old;
	unsigned long flags;

	sc = lookup_swap_cgroup(ent, &ctrl);

	spin_lock_irqsave(&ctrl->lock, flags);
	old = sc->id;
	sc->id = id;
	spin_unlock_irqrestore(&ctrl->lock, flags);

	return old;
}

/**
 * lookup_swap_cgroup_id - lookup mem_cgroup id 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_id(swp_entry_t ent)
{
	return lookup_swap_cgroup(ent, NULL)->id;
}

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 = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
	array_size = length * sizeof(void *);

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

	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;
		mutex_unlock(&swap_cgroup_mutex);
		vfree(array);
		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 swapaccount=0 boot option\n");
	return -ENOMEM;
}

void swap_cgroup_swapoff(int type)
{
	struct page **map;
	unsigned long i, length;
	struct swap_cgroup_ctrl *ctrl;

	if (!do_swap_account)
		return;

	mutex_lock(&swap_cgroup_mutex);
	ctrl = &swap_cgroup_ctrl[type];
	map = ctrl->map;
	length = ctrl->length;
	ctrl->map = NULL;
	ctrl->length = 0;
	mutex_unlock(&swap_cgroup_mutex);

	if (map) {
		for (i = 0; i < length; i++) {
			struct page *page = map[i];
			if (page)
				__free_page(page);
		}
		vfree(map);
	}
}

#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
52d4b9ac KH	14	static unsigned long total_usage;
	15
	16	#if !defined(CONFIG_SPARSEMEM)
	17
	18
31168481	19	void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
52d4b9ac KH	20	{
	21	pgdat->node_page_cgroup = NULL;
	22	}
	23
	24	struct page_cgroup lookup_page_cgroup(struct page page)
	25	{
	26	unsigned long pfn = page_to_pfn(page);
	27	unsigned long offset;
	28	struct page_cgroup *base;
	29
	30	base = NODE_DATA(page_to_nid(page))->node_page_cgroup;
00c54c0b JW	31	#ifdef CONFIG_DEBUG_VM
	32	/*
	33	* The sanity checks the page allocator does upon freeing a
	34	* page can reach here before the page_cgroup arrays are
	35	* allocated when feeding a range of pages to the allocator
	36	* for the first time during bootup or memory hotplug.
	37	*/
52d4b9ac KH	38	if (unlikely(!base))
52d4b9ac KH	39	return NULL;
00c54c0b	40	#endif
52d4b9ac KH	41	offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn;
	42	return base + offset;
	43	}
	44
	45	static int __init alloc_node_page_cgroup(int nid)
	46	{
6b208e3f	47	struct page_cgroup *base;
52d4b9ac	48	unsigned long table_size;
6b208e3f	49	unsigned long nr_pages;
52d4b9ac	50
52d4b9ac	51	nr_pages = NODE_DATA(nid)->node_spanned_pages;
653d22c0 KH	52	if (!nr_pages)
	53	return 0;
	54
52d4b9ac	55	table_size = sizeof(struct page_cgroup) * nr_pages;
ca371c0d KH	56
	57	base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
	58	table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
	59	if (!base)
52d4b9ac	60	return -ENOMEM;
52d4b9ac KH	61	NODE_DATA(nid)->node_page_cgroup = base;
	62	total_usage += table_size;
	63	return 0;
	64	}
	65
ca371c0d	66	void __init page_cgroup_init_flatmem(void)
52d4b9ac KH	67	{
	68
	69	int nid, fail;
	70
f8d66542	71	if (mem_cgroup_disabled())
94b6da5a KH	72	return;
94b6da5a KH	73
52d4b9ac KH	74	for_each_online_node(nid) {
	75	fail = alloc_node_page_cgroup(nid);
	76	if (fail)
	77	goto fail;
	78	}
	79	printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
8ca739e3 RD	80	printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
8ca739e3 RD	81	" don't want memory cgroups\n");
52d4b9ac KH	82	return;
52d4b9ac KH	83	fail:
8ca739e3 RD	84	printk(KERN_CRIT "allocation of page_cgroup failed.\n");
8ca739e3 RD	85	printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
52d4b9ac KH	86	panic("Out of memory");
	87	}
	88
	89	#else /* CONFIG_FLAT_NODE_MEM_MAP */
	90
	91	struct page_cgroup lookup_page_cgroup(struct page page)
	92	{
	93	unsigned long pfn = page_to_pfn(page);
	94	struct mem_section *section = __pfn_to_section(pfn);
00c54c0b JW	95	#ifdef CONFIG_DEBUG_VM
	96	/*
	97	* The sanity checks the page allocator does upon freeing a
	98	* page can reach here before the page_cgroup arrays are
	99	* allocated when feeding a range of pages to the allocator
	100	* for the first time during bootup or memory hotplug.
	101	*/
d69b042f BS	102	if (!section->page_cgroup)
d69b042f BS	103	return NULL;
00c54c0b	104	#endif
52d4b9ac KH	105	return section->page_cgroup + pfn;
	106	}
	107
268433b8	108	static void *__meminit alloc_page_cgroup(size_t size, int nid)
dde79e00	109	{
6b208e3f	110	gfp_t flags = GFP_KERNEL \| __GFP_ZERO \| __GFP_NOWARN;
dde79e00 MH	111	void *addr = NULL;
dde79e00 MH	112
ff7ee93f SR	113	addr = alloc_pages_exact_nid(nid, size, flags);
	114	if (addr) {
	115	kmemleak_alloc(addr, size, 1, flags);
dde79e00	116	return addr;
ff7ee93f	117	}
dde79e00 MH	118
dde79e00 MH	119	if (node_state(nid, N_HIGH_MEMORY))
6b208e3f	120	addr = vzalloc_node(size, nid);
dde79e00	121	else
6b208e3f	122	addr = vzalloc(size);
dde79e00 MH	123
	124	return addr;
	125	}
	126
37573e8c	127	static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
52d4b9ac	128	{
6b3ae58e	129	struct mem_section *section;
6b208e3f	130	struct page_cgroup *base;
52d4b9ac	131	unsigned long table_size;
52d4b9ac	132
6b208e3f	133	section = __pfn_to_section(pfn);
6b3ae58e JW	134
	135	if (section->page_cgroup)
	136	return 0;
	137
6b3ae58e	138	table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
dde79e00 MH	139	base = alloc_page_cgroup(table_size, nid);
dde79e00 MH	140
6b3ae58e JW	141	/*
	142	* The value stored in section->page_cgroup is (base - pfn)
	143	* and it does not point to the memory block allocated above,
	144	* causing kmemleak false positives.
	145	*/
	146	kmemleak_not_leak(base);
52d4b9ac KH	147
	148	if (!base) {
	149	printk(KERN_ERR "page cgroup allocation failure\n");
	150	return -ENOMEM;
	151	}
	152
37573e8c KH	153	/*
	154	* The passed "pfn" may not be aligned to SECTION. For the calculation
	155	* we need to apply a mask.
	156	*/
	157	pfn &= PAGE_SECTION_MASK;
52d4b9ac KH	158	section->page_cgroup = base - pfn;
	159	total_usage += table_size;
	160	return 0;
	161	}
	162	#ifdef CONFIG_MEMORY_HOTPLUG
0efc8eb9 BL	163	static void free_page_cgroup(void *addr)
	164	{
	165	if (is_vmalloc_addr(addr)) {
	166	vfree(addr);
	167	} else {
	168	struct page *page = virt_to_page(addr);
	169	size_t table_size =
	170	sizeof(struct page_cgroup) * PAGES_PER_SECTION;
	171
	172	BUG_ON(PageReserved(page));
	173	free_pages_exact(addr, table_size);
	174	}
	175	}
	176
52d4b9ac KH	177	void __free_page_cgroup(unsigned long pfn)
	178	{
	179	struct mem_section *ms;
	180	struct page_cgroup *base;
	181
	182	ms = __pfn_to_section(pfn);
	183	if (!ms \|\| !ms->page_cgroup)
	184	return;
	185	base = ms->page_cgroup + pfn;
dde79e00 MH	186	free_page_cgroup(base);
dde79e00 MH	187	ms->page_cgroup = NULL;
52d4b9ac KH	188	}
52d4b9ac KH	189
31168481	190	int __meminit online_page_cgroup(unsigned long start_pfn,
52d4b9ac KH	191	unsigned long nr_pages,
	192	int nid)
	193	{
	194	unsigned long start, end, pfn;
	195	int fail = 0;
	196
1bb36fbd DK	197	start = SECTION_ALIGN_DOWN(start_pfn);
1bb36fbd DK	198	end = SECTION_ALIGN_UP(start_pfn + nr_pages);
52d4b9ac	199
37573e8c KH	200	if (nid == -1) {
	201	/*
	202	* In this case, "nid" already exists and contains valid memory.
	203	* "start_pfn" passed to us is a pfn which is an arg for
	204	* online__pages(), and start_pfn should exist.
	205	*/
	206	nid = pfn_to_nid(start_pfn);
	207	VM_BUG_ON(!node_state(nid, N_ONLINE));
	208	}
	209
52d4b9ac KH	210	for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
	211	if (!pfn_present(pfn))
	212	continue;
37573e8c	213	fail = init_section_page_cgroup(pfn, nid);
52d4b9ac KH	214	}
	215	if (!fail)
	216	return 0;
	217
	218	/* rollback */
	219	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
	220	__free_page_cgroup(pfn);
	221
	222	return -ENOMEM;
	223	}
	224
31168481	225	int __meminit offline_page_cgroup(unsigned long start_pfn,
52d4b9ac KH	226	unsigned long nr_pages, int nid)
	227	{
	228	unsigned long start, end, pfn;
	229
1bb36fbd DK	230	start = SECTION_ALIGN_DOWN(start_pfn);
1bb36fbd DK	231	end = SECTION_ALIGN_UP(start_pfn + nr_pages);
52d4b9ac KH	232
	233	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
	234	__free_page_cgroup(pfn);
	235	return 0;
	236
	237	}
	238
31168481	239	static int __meminit page_cgroup_callback(struct notifier_block *self,
52d4b9ac KH	240	unsigned long action, void *arg)
	241	{
	242	struct memory_notify *mn = arg;
	243	int ret = 0;
	244	switch (action) {
	245	case MEM_GOING_ONLINE:
	246	ret = online_page_cgroup(mn->start_pfn,
	247	mn->nr_pages, mn->status_change_nid);
	248	break;
52d4b9ac KH	249	case MEM_OFFLINE:
	250	offline_page_cgroup(mn->start_pfn,
	251	mn->nr_pages, mn->status_change_nid);
	252	break;
dc19f9db	253	case MEM_CANCEL_ONLINE:
7c72eb32 WC	254	offline_page_cgroup(mn->start_pfn,
	255	mn->nr_pages, mn->status_change_nid);
	256	break;
52d4b9ac KH	257	case MEM_GOING_OFFLINE:
	258	break;
	259	case MEM_ONLINE:
	260	case MEM_CANCEL_OFFLINE:
	261	break;
	262	}
dc19f9db	263
5fda1bd5	264	return notifier_from_errno(ret);
52d4b9ac KH	265	}
	266
	267	#endif
	268
	269	void __init page_cgroup_init(void)
	270	{
	271	unsigned long pfn;
37573e8c	272	int nid;
52d4b9ac	273
f8d66542	274	if (mem_cgroup_disabled())
94b6da5a KH	275	return;
94b6da5a KH	276
31aaea4a	277	for_each_node_state(nid, N_MEMORY) {
37573e8c KH	278	unsigned long start_pfn, end_pfn;
	279
	280	start_pfn = node_start_pfn(nid);
	281	end_pfn = node_end_pfn(nid);
	282	/*
	283	* start_pfn and end_pfn may not be aligned to SECTION and the
	284	* page->flags of out of node pages are not initialized. So we
	285	* scan [start_pfn, the biggest section's pfn < end_pfn) here.
	286	*/
	287	for (pfn = start_pfn;
	288	pfn < end_pfn;
	289	pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) {
	290
	291	if (!pfn_valid(pfn))
	292	continue;
	293	/*
	294	* Nodes's pfns can be overlapping.
	295	* We know some arch can have a nodes layout such as
	296	* -------------pfn-------------->
	297	* N0 \| N1 \| N2 \| N0 \| N1 \| N2\|....
	298	*/
	299	if (pfn_to_nid(pfn) != nid)
	300	continue;
	301	if (init_section_page_cgroup(pfn, nid))
	302	goto oom;
	303	}
52d4b9ac	304	}
37573e8c	305	hotplug_memory_notifier(page_cgroup_callback, 0);
52d4b9ac	306	printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
37573e8c KH	307	printk(KERN_INFO "please try 'cgroup_disable=memory' option if you "
	308	"don't want memory cgroups\n");
	309	return;
	310	oom:
	311	printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
	312	panic("Out of memory");
52d4b9ac KH	313	}
52d4b9ac KH	314
31168481	315	void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
52d4b9ac KH	316	{
	317	return;
	318	}
	319
	320	#endif
27a7faa0 KH	321
27a7faa0 KH	322
c255a458	323	#ifdef CONFIG_MEMCG_SWAP
27a7faa0 KH	324
	325	static DEFINE_MUTEX(swap_cgroup_mutex);
	326	struct swap_cgroup_ctrl {
	327	struct page **map;
	328	unsigned long length;
e9e58a4e	329	spinlock_t lock;
27a7faa0 KH	330	};
27a7faa0 KH	331
61600f57	332	static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
27a7faa0	333
27a7faa0	334	struct swap_cgroup {
a3b2d692	335	unsigned short id;
27a7faa0 KH	336	};
27a7faa0 KH	337	#define SC_PER_PAGE (PAGE_SIZE/sizeof(struct swap_cgroup))
27a7faa0 KH	338
	339	/*
	340	* SwapCgroup implements "lookup" and "exchange" operations.
	341	* In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
	342	* against SwapCache. At swap_free(), this is accessed directly from swap.
	343	*
	344	* This means,
	345	* - we have no race in "exchange" when we're accessed via SwapCache because
	346	* SwapCache(and its swp_entry) is under lock.
	347	* - When called via swap_free(), there is no user of this entry and no race.
	348	* Then, we don't need lock around "exchange".
	349	*
	350	* TODO: we can push these buffers out to HIGHMEM.
	351	*/
	352
	353	/*
	354	* allocate buffer for swap_cgroup.
	355	*/
	356	static int swap_cgroup_prepare(int type)
	357	{
	358	struct page *page;
	359	struct swap_cgroup_ctrl *ctrl;
	360	unsigned long idx, max;
	361
27a7faa0 KH	362	ctrl = &swap_cgroup_ctrl[type];
	363
	364	for (idx = 0; idx < ctrl->length; idx++) {
	365	page = alloc_page(GFP_KERNEL \| __GFP_ZERO);
	366	if (!page)
	367	goto not_enough_page;
	368	ctrl->map[idx] = page;
	369	}
	370	return 0;
	371	not_enough_page:
	372	max = idx;
	373	for (idx = 0; idx < max; idx++)
	374	__free_page(ctrl->map[idx]);
	375
	376	return -ENOMEM;
	377	}
	378
9fb4b7cc BL	379	static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
	380	struct swap_cgroup_ctrl **ctrlp)
	381	{
	382	pgoff_t offset = swp_offset(ent);
	383	struct swap_cgroup_ctrl *ctrl;
	384	struct page *mappage;
c09ff089	385	struct swap_cgroup *sc;
9fb4b7cc BL	386
	387	ctrl = &swap_cgroup_ctrl[swp_type(ent)];
	388	if (ctrlp)
	389	*ctrlp = ctrl;
	390
	391	mappage = ctrl->map[offset / SC_PER_PAGE];
c09ff089 HD	392	sc = page_address(mappage);
c09ff089 HD	393	return sc + offset % SC_PER_PAGE;
9fb4b7cc BL	394	}
9fb4b7cc BL	395
02491447 DN	396	/**
02491447 DN	397	* swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
dad7557e	398	* @ent: swap entry to be cmpxchged
02491447 DN	399	* @old: old id
	400	* @new: new id
	401	*
	402	* Returns old id at success, 0 at failure.
25985edc	403	* (There is no mem_cgroup using 0 as its id)
02491447 DN	404	*/
	405	unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
	406	unsigned short old, unsigned short new)
	407	{
02491447	408	struct swap_cgroup_ctrl *ctrl;
02491447	409	struct swap_cgroup *sc;
e9e58a4e KH	410	unsigned long flags;
e9e58a4e KH	411	unsigned short retval;
02491447	412
9fb4b7cc	413	sc = lookup_swap_cgroup(ent, &ctrl);
02491447	414
e9e58a4e KH	415	spin_lock_irqsave(&ctrl->lock, flags);
	416	retval = sc->id;
	417	if (retval == old)
	418	sc->id = new;
02491447	419	else
e9e58a4e KH	420	retval = 0;
	421	spin_unlock_irqrestore(&ctrl->lock, flags);
	422	return retval;
02491447 DN	423	}
02491447 DN	424
27a7faa0 KH	425	/**
	426	* swap_cgroup_record - record mem_cgroup for this swp_entry.
	427	* @ent: swap entry to be recorded into
dad7557e	428	* @id: mem_cgroup to be recorded
27a7faa0	429	*
a3b2d692 KH	430	* Returns old value at success, 0 at failure.
a3b2d692 KH	431	* (Of course, old value can be 0.)
27a7faa0	432	*/
a3b2d692	433	unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
27a7faa0	434	{
27a7faa0	435	struct swap_cgroup_ctrl *ctrl;
27a7faa0	436	struct swap_cgroup *sc;
a3b2d692	437	unsigned short old;
e9e58a4e	438	unsigned long flags;
27a7faa0	439
9fb4b7cc	440	sc = lookup_swap_cgroup(ent, &ctrl);
27a7faa0	441
e9e58a4e KH	442	spin_lock_irqsave(&ctrl->lock, flags);
	443	old = sc->id;
	444	sc->id = id;
	445	spin_unlock_irqrestore(&ctrl->lock, flags);
27a7faa0 KH	446
	447	return old;
	448	}
	449
	450	/**
9fb4b7cc	451	* lookup_swap_cgroup_id - lookup mem_cgroup id tied to swap entry
27a7faa0 KH	452	* @ent: swap entry to be looked up.
27a7faa0 KH	453	*
a3b2d692	454	* Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
27a7faa0	455	*/
9fb4b7cc	456	unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
27a7faa0	457	{
9fb4b7cc	458	return lookup_swap_cgroup(ent, NULL)->id;
27a7faa0 KH	459	}
	460
	461	int swap_cgroup_swapon(int type, unsigned long max_pages)
	462	{
	463	void *array;
	464	unsigned long array_size;
	465	unsigned long length;
	466	struct swap_cgroup_ctrl *ctrl;
	467
	468	if (!do_swap_account)
	469	return 0;
	470
33278f7f	471	length = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
27a7faa0 KH	472	array_size = length * sizeof(void *);
27a7faa0 KH	473
8c1fec1b	474	array = vzalloc(array_size);
27a7faa0 KH	475	if (!array)
	476	goto nomem;
	477
27a7faa0 KH	478	ctrl = &swap_cgroup_ctrl[type];
	479	mutex_lock(&swap_cgroup_mutex);
	480	ctrl->length = length;
	481	ctrl->map = array;
e9e58a4e	482	spin_lock_init(&ctrl->lock);
27a7faa0 KH	483	if (swap_cgroup_prepare(type)) {
	484	/* memory shortage */
	485	ctrl->map = NULL;
	486	ctrl->length = 0;
27a7faa0	487	mutex_unlock(&swap_cgroup_mutex);
6a5b18d2	488	vfree(array);
27a7faa0 KH	489	goto nomem;
	490	}
	491	mutex_unlock(&swap_cgroup_mutex);
	492
27a7faa0 KH	493	return 0;
	494	nomem:
	495	printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
	496	printk(KERN_INFO
00a66d29	497	"swap_cgroup can be disabled by swapaccount=0 boot option\n");
27a7faa0 KH	498	return -ENOMEM;
	499	}
	500
	501	void swap_cgroup_swapoff(int type)
	502	{
6a5b18d2 NK	503	struct page **map;
6a5b18d2 NK	504	unsigned long i, length;
27a7faa0 KH	505	struct swap_cgroup_ctrl *ctrl;
	506
	507	if (!do_swap_account)
	508	return;
	509
	510	mutex_lock(&swap_cgroup_mutex);
	511	ctrl = &swap_cgroup_ctrl[type];
6a5b18d2 NK	512	map = ctrl->map;
	513	length = ctrl->length;
	514	ctrl->map = NULL;
	515	ctrl->length = 0;
	516	mutex_unlock(&swap_cgroup_mutex);
	517
	518	if (map) {
	519	for (i = 0; i < length; i++) {
	520	struct page *page = map[i];
27a7faa0 KH	521	if (page)
	522	__free_page(page);
	523	}
6a5b18d2	524	vfree(map);
27a7faa0	525	}
27a7faa0 KH	526	}
	527
	528	#endif