[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;
	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;
	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);

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

#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);
	}
}
#endif

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
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:
	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_HIGH_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_CGROUP_MEM_RES_CTLR_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))
#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 using 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 = 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;
	31	if (unlikely(!base))
	32	return NULL;
	33
	34	offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn;
	35	return base + offset;
	36	}
	37
	38	static int __init alloc_node_page_cgroup(int nid)
	39	{
6b208e3f	40	struct page_cgroup *base;
52d4b9ac	41	unsigned long table_size;
6b208e3f	42	unsigned long nr_pages;
52d4b9ac	43
52d4b9ac	44	nr_pages = NODE_DATA(nid)->node_spanned_pages;
653d22c0 KH	45	if (!nr_pages)
	46	return 0;
	47
52d4b9ac	48	table_size = sizeof(struct page_cgroup) * nr_pages;
ca371c0d KH	49
	50	base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
	51	table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
	52	if (!base)
52d4b9ac	53	return -ENOMEM;
52d4b9ac KH	54	NODE_DATA(nid)->node_page_cgroup = base;
	55	total_usage += table_size;
	56	return 0;
	57	}
	58
ca371c0d	59	void __init page_cgroup_init_flatmem(void)
52d4b9ac KH	60	{
	61
	62	int nid, fail;
	63
f8d66542	64	if (mem_cgroup_disabled())
94b6da5a KH	65	return;
94b6da5a KH	66
52d4b9ac KH	67	for_each_online_node(nid) {
	68	fail = alloc_node_page_cgroup(nid);
	69	if (fail)
	70	goto fail;
	71	}
	72	printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
8ca739e3 RD	73	printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
8ca739e3 RD	74	" don't want memory cgroups\n");
52d4b9ac KH	75	return;
52d4b9ac KH	76	fail:
8ca739e3 RD	77	printk(KERN_CRIT "allocation of page_cgroup failed.\n");
8ca739e3 RD	78	printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
52d4b9ac KH	79	panic("Out of memory");
	80	}
	81
	82	#else /* CONFIG_FLAT_NODE_MEM_MAP */
	83
	84	struct page_cgroup lookup_page_cgroup(struct page page)
	85	{
	86	unsigned long pfn = page_to_pfn(page);
	87	struct mem_section *section = __pfn_to_section(pfn);
	88
d69b042f BS	89	if (!section->page_cgroup)
d69b042f BS	90	return NULL;
52d4b9ac KH	91	return section->page_cgroup + pfn;
	92	}
	93
268433b8	94	static void *__meminit alloc_page_cgroup(size_t size, int nid)
dde79e00	95	{
6b208e3f	96	gfp_t flags = GFP_KERNEL \| __GFP_ZERO \| __GFP_NOWARN;
dde79e00 MH	97	void *addr = NULL;
dde79e00 MH	98
ff7ee93f SR	99	addr = alloc_pages_exact_nid(nid, size, flags);
	100	if (addr) {
	101	kmemleak_alloc(addr, size, 1, flags);
dde79e00	102	return addr;
ff7ee93f	103	}
dde79e00 MH	104
dde79e00 MH	105	if (node_state(nid, N_HIGH_MEMORY))
6b208e3f	106	addr = vzalloc_node(size, nid);
dde79e00	107	else
6b208e3f	108	addr = vzalloc(size);
dde79e00 MH	109
	110	return addr;
	111	}
	112
	113	#ifdef CONFIG_MEMORY_HOTPLUG
	114	static void free_page_cgroup(void *addr)
	115	{
	116	if (is_vmalloc_addr(addr)) {
	117	vfree(addr);
	118	} else {
	119	struct page *page = virt_to_page(addr);
6cfddb26 MH	120	size_t table_size =
	121	sizeof(struct page_cgroup) * PAGES_PER_SECTION;
	122
	123	BUG_ON(PageReserved(page));
	124	free_pages_exact(addr, table_size);
dde79e00 MH	125	}
	126	}
	127	#endif
	128
37573e8c	129	static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
52d4b9ac	130	{
6b3ae58e	131	struct mem_section *section;
6b208e3f	132	struct page_cgroup *base;
52d4b9ac	133	unsigned long table_size;
52d4b9ac	134
6b208e3f	135	section = __pfn_to_section(pfn);
6b3ae58e JW	136
	137	if (section->page_cgroup)
	138	return 0;
	139
6b3ae58e	140	table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
dde79e00 MH	141	base = alloc_page_cgroup(table_size, nid);
dde79e00 MH	142
6b3ae58e JW	143	/*
	144	* The value stored in section->page_cgroup is (base - pfn)
	145	* and it does not point to the memory block allocated above,
	146	* causing kmemleak false positives.
	147	*/
	148	kmemleak_not_leak(base);
52d4b9ac KH	149
	150	if (!base) {
	151	printk(KERN_ERR "page cgroup allocation failure\n");
	152	return -ENOMEM;
	153	}
	154
37573e8c KH	155	/*
	156	* The passed "pfn" may not be aligned to SECTION. For the calculation
	157	* we need to apply a mask.
	158	*/
	159	pfn &= PAGE_SECTION_MASK;
52d4b9ac KH	160	section->page_cgroup = base - pfn;
	161	total_usage += table_size;
	162	return 0;
	163	}
	164	#ifdef CONFIG_MEMORY_HOTPLUG
	165	void __free_page_cgroup(unsigned long pfn)
	166	{
	167	struct mem_section *ms;
	168	struct page_cgroup *base;
	169
	170	ms = __pfn_to_section(pfn);
	171	if (!ms \|\| !ms->page_cgroup)
	172	return;
	173	base = ms->page_cgroup + pfn;
dde79e00 MH	174	free_page_cgroup(base);
dde79e00 MH	175	ms->page_cgroup = NULL;
52d4b9ac KH	176	}
52d4b9ac KH	177
31168481	178	int __meminit online_page_cgroup(unsigned long start_pfn,
52d4b9ac KH	179	unsigned long nr_pages,
	180	int nid)
	181	{
	182	unsigned long start, end, pfn;
	183	int fail = 0;
	184
1bb36fbd DK	185	start = SECTION_ALIGN_DOWN(start_pfn);
1bb36fbd DK	186	end = SECTION_ALIGN_UP(start_pfn + nr_pages);
52d4b9ac	187
37573e8c KH	188	if (nid == -1) {
	189	/*
	190	* In this case, "nid" already exists and contains valid memory.
	191	* "start_pfn" passed to us is a pfn which is an arg for
	192	* online__pages(), and start_pfn should exist.
	193	*/
	194	nid = pfn_to_nid(start_pfn);
	195	VM_BUG_ON(!node_state(nid, N_ONLINE));
	196	}
	197
52d4b9ac KH	198	for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
	199	if (!pfn_present(pfn))
	200	continue;
37573e8c	201	fail = init_section_page_cgroup(pfn, nid);
52d4b9ac KH	202	}
	203	if (!fail)
	204	return 0;
	205
	206	/* rollback */
	207	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
	208	__free_page_cgroup(pfn);
	209
	210	return -ENOMEM;
	211	}
	212
31168481	213	int __meminit offline_page_cgroup(unsigned long start_pfn,
52d4b9ac KH	214	unsigned long nr_pages, int nid)
	215	{
	216	unsigned long start, end, pfn;
	217
1bb36fbd DK	218	start = SECTION_ALIGN_DOWN(start_pfn);
1bb36fbd DK	219	end = SECTION_ALIGN_UP(start_pfn + nr_pages);
52d4b9ac KH	220
	221	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
	222	__free_page_cgroup(pfn);
	223	return 0;
	224
	225	}
	226
31168481	227	static int __meminit page_cgroup_callback(struct notifier_block *self,
52d4b9ac KH	228	unsigned long action, void *arg)
	229	{
	230	struct memory_notify *mn = arg;
	231	int ret = 0;
	232	switch (action) {
	233	case MEM_GOING_ONLINE:
	234	ret = online_page_cgroup(mn->start_pfn,
	235	mn->nr_pages, mn->status_change_nid);
	236	break;
52d4b9ac KH	237	case MEM_OFFLINE:
	238	offline_page_cgroup(mn->start_pfn,
	239	mn->nr_pages, mn->status_change_nid);
	240	break;
dc19f9db	241	case MEM_CANCEL_ONLINE:
52d4b9ac KH	242	case MEM_GOING_OFFLINE:
	243	break;
	244	case MEM_ONLINE:
	245	case MEM_CANCEL_OFFLINE:
	246	break;
	247	}
dc19f9db	248
5fda1bd5	249	return notifier_from_errno(ret);
52d4b9ac KH	250	}
	251
	252	#endif
	253
	254	void __init page_cgroup_init(void)
	255	{
	256	unsigned long pfn;
37573e8c	257	int nid;
52d4b9ac	258
f8d66542	259	if (mem_cgroup_disabled())
94b6da5a KH	260	return;
94b6da5a KH	261
37573e8c KH	262	for_each_node_state(nid, N_HIGH_MEMORY) {
	263	unsigned long start_pfn, end_pfn;
	264
	265	start_pfn = node_start_pfn(nid);
	266	end_pfn = node_end_pfn(nid);
	267	/*
	268	* start_pfn and end_pfn may not be aligned to SECTION and the
	269	* page->flags of out of node pages are not initialized. So we
	270	* scan [start_pfn, the biggest section's pfn < end_pfn) here.
	271	*/
	272	for (pfn = start_pfn;
	273	pfn < end_pfn;
	274	pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) {
	275
	276	if (!pfn_valid(pfn))
	277	continue;
	278	/*
	279	* Nodes's pfns can be overlapping.
	280	* We know some arch can have a nodes layout such as
	281	* -------------pfn-------------->
	282	* N0 \| N1 \| N2 \| N0 \| N1 \| N2\|....
	283	*/
	284	if (pfn_to_nid(pfn) != nid)
	285	continue;
	286	if (init_section_page_cgroup(pfn, nid))
	287	goto oom;
	288	}
52d4b9ac	289	}
37573e8c	290	hotplug_memory_notifier(page_cgroup_callback, 0);
52d4b9ac	291	printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
37573e8c KH	292	printk(KERN_INFO "please try 'cgroup_disable=memory' option if you "
	293	"don't want memory cgroups\n");
	294	return;
	295	oom:
	296	printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
	297	panic("Out of memory");
52d4b9ac KH	298	}
52d4b9ac KH	299
31168481	300	void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
52d4b9ac KH	301	{
	302	return;
	303	}
	304
	305	#endif
27a7faa0 KH	306
	307
	308	#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
	309
	310	static DEFINE_MUTEX(swap_cgroup_mutex);
	311	struct swap_cgroup_ctrl {
	312	struct page **map;
	313	unsigned long length;
e9e58a4e	314	spinlock_t lock;
27a7faa0 KH	315	};
27a7faa0 KH	316
61600f57	317	static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
27a7faa0	318
27a7faa0	319	struct swap_cgroup {
a3b2d692	320	unsigned short id;
27a7faa0 KH	321	};
	322	#define SC_PER_PAGE (PAGE_SIZE/sizeof(struct swap_cgroup))
	323	#define SC_POS_MASK (SC_PER_PAGE - 1)
	324
	325	/*
	326	* SwapCgroup implements "lookup" and "exchange" operations.
	327	* In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
	328	* against SwapCache. At swap_free(), this is accessed directly from swap.
	329	*
	330	* This means,
	331	* - we have no race in "exchange" when we're accessed via SwapCache because
	332	* SwapCache(and its swp_entry) is under lock.
	333	* - When called via swap_free(), there is no user of this entry and no race.
	334	* Then, we don't need lock around "exchange".
	335	*
	336	* TODO: we can push these buffers out to HIGHMEM.
	337	*/
	338
	339	/*
	340	* allocate buffer for swap_cgroup.
	341	*/
	342	static int swap_cgroup_prepare(int type)
	343	{
	344	struct page *page;
	345	struct swap_cgroup_ctrl *ctrl;
	346	unsigned long idx, max;
	347
27a7faa0 KH	348	ctrl = &swap_cgroup_ctrl[type];
	349
	350	for (idx = 0; idx < ctrl->length; idx++) {
	351	page = alloc_page(GFP_KERNEL \| __GFP_ZERO);
	352	if (!page)
	353	goto not_enough_page;
	354	ctrl->map[idx] = page;
	355	}
	356	return 0;
	357	not_enough_page:
	358	max = idx;
	359	for (idx = 0; idx < max; idx++)
	360	__free_page(ctrl->map[idx]);
	361
	362	return -ENOMEM;
	363	}
	364
02491447 DN	365	/**
	366	* swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
	367	* @end: swap entry to be cmpxchged
	368	* @old: old id
	369	* @new: new id
	370	*
	371	* Returns old id at success, 0 at failure.
25985edc	372	* (There is no mem_cgroup using 0 as its id)
02491447 DN	373	*/
	374	unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
	375	unsigned short old, unsigned short new)
	376	{
	377	int type = swp_type(ent);
	378	unsigned long offset = swp_offset(ent);
	379	unsigned long idx = offset / SC_PER_PAGE;
	380	unsigned long pos = offset & SC_POS_MASK;
	381	struct swap_cgroup_ctrl *ctrl;
	382	struct page *mappage;
	383	struct swap_cgroup *sc;
e9e58a4e KH	384	unsigned long flags;
e9e58a4e KH	385	unsigned short retval;
02491447 DN	386
	387	ctrl = &swap_cgroup_ctrl[type];
	388
	389	mappage = ctrl->map[idx];
	390	sc = page_address(mappage);
	391	sc += pos;
e9e58a4e KH	392	spin_lock_irqsave(&ctrl->lock, flags);
	393	retval = sc->id;
	394	if (retval == old)
	395	sc->id = new;
02491447	396	else
e9e58a4e KH	397	retval = 0;
	398	spin_unlock_irqrestore(&ctrl->lock, flags);
	399	return retval;
02491447 DN	400	}
02491447 DN	401
27a7faa0 KH	402	/**
	403	* swap_cgroup_record - record mem_cgroup for this swp_entry.
	404	* @ent: swap entry to be recorded into
	405	* @mem: mem_cgroup to be recorded
	406	*
a3b2d692 KH	407	* Returns old value at success, 0 at failure.
a3b2d692 KH	408	* (Of course, old value can be 0.)
27a7faa0	409	*/
a3b2d692	410	unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
27a7faa0 KH	411	{
	412	int type = swp_type(ent);
	413	unsigned long offset = swp_offset(ent);
	414	unsigned long idx = offset / SC_PER_PAGE;
	415	unsigned long pos = offset & SC_POS_MASK;
	416	struct swap_cgroup_ctrl *ctrl;
	417	struct page *mappage;
	418	struct swap_cgroup *sc;
a3b2d692	419	unsigned short old;
e9e58a4e	420	unsigned long flags;
27a7faa0	421
27a7faa0 KH	422	ctrl = &swap_cgroup_ctrl[type];
	423
	424	mappage = ctrl->map[idx];
	425	sc = page_address(mappage);
	426	sc += pos;
e9e58a4e KH	427	spin_lock_irqsave(&ctrl->lock, flags);
	428	old = sc->id;
	429	sc->id = id;
	430	spin_unlock_irqrestore(&ctrl->lock, flags);
27a7faa0 KH	431
	432	return old;
	433	}
	434
	435	/**
	436	* lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
	437	* @ent: swap entry to be looked up.
	438	*
a3b2d692	439	* Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
27a7faa0	440	*/
a3b2d692	441	unsigned short lookup_swap_cgroup(swp_entry_t ent)
27a7faa0 KH	442	{
	443	int type = swp_type(ent);
	444	unsigned long offset = swp_offset(ent);
	445	unsigned long idx = offset / SC_PER_PAGE;
	446	unsigned long pos = offset & SC_POS_MASK;
	447	struct swap_cgroup_ctrl *ctrl;
	448	struct page *mappage;
	449	struct swap_cgroup *sc;
a3b2d692	450	unsigned short ret;
27a7faa0	451
27a7faa0 KH	452	ctrl = &swap_cgroup_ctrl[type];
	453	mappage = ctrl->map[idx];
	454	sc = page_address(mappage);
	455	sc += pos;
a3b2d692	456	ret = sc->id;
27a7faa0 KH	457	return ret;
	458	}
	459
	460	int swap_cgroup_swapon(int type, unsigned long max_pages)
	461	{
	462	void *array;
	463	unsigned long array_size;
	464	unsigned long length;
	465	struct swap_cgroup_ctrl *ctrl;
	466
	467	if (!do_swap_account)
	468	return 0;
	469
33278f7f	470	length = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
27a7faa0 KH	471	array_size = length * sizeof(void *);
27a7faa0 KH	472
8c1fec1b	473	array = vzalloc(array_size);
27a7faa0 KH	474	if (!array)
	475	goto nomem;
	476
27a7faa0 KH	477	ctrl = &swap_cgroup_ctrl[type];
	478	mutex_lock(&swap_cgroup_mutex);
	479	ctrl->length = length;
	480	ctrl->map = array;
e9e58a4e	481	spin_lock_init(&ctrl->lock);
27a7faa0 KH	482	if (swap_cgroup_prepare(type)) {
	483	/* memory shortage */
	484	ctrl->map = NULL;
	485	ctrl->length = 0;
27a7faa0	486	mutex_unlock(&swap_cgroup_mutex);
6a5b18d2	487	vfree(array);
27a7faa0 KH	488	goto nomem;
	489	}
	490	mutex_unlock(&swap_cgroup_mutex);
	491
27a7faa0 KH	492	return 0;
	493	nomem:
	494	printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
	495	printk(KERN_INFO
00a66d29	496	"swap_cgroup can be disabled by swapaccount=0 boot option\n");
27a7faa0 KH	497	return -ENOMEM;
	498	}
	499
	500	void swap_cgroup_swapoff(int type)
	501	{
6a5b18d2 NK	502	struct page **map;
6a5b18d2 NK	503	unsigned long i, length;
27a7faa0 KH	504	struct swap_cgroup_ctrl *ctrl;
	505
	506	if (!do_swap_account)
	507	return;
	508
	509	mutex_lock(&swap_cgroup_mutex);
	510	ctrl = &swap_cgroup_ctrl[type];
6a5b18d2 NK	511	map = ctrl->map;
	512	length = ctrl->length;
	513	ctrl->map = NULL;
	514	ctrl->length = 0;
	515	mutex_unlock(&swap_cgroup_mutex);
	516
	517	if (map) {
	518	for (i = 0; i < length; i++) {
	519	struct page *page = map[i];
27a7faa0 KH	520	if (page)
	521	__free_page(page);
	522	}
6a5b18d2	523	vfree(map);
27a7faa0	524	}
27a7faa0 KH	525	}
	526
	527	#endif