- 根目录:
- 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:
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))
/*
* 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;
ctrl = &swap_cgroup_ctrl[swp_type(ent)];
if (ctrlp)
*ctrlp = ctrl;
mappage = ctrl->map[offset / SC_PER_PAGE];
return page_address(mappage) + offset % SC_PER_PAGE;
}
/**
* 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)
{
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
* @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)
{
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