linux/mm/page_cgroup.c
Daisuke Nishimura 024914477e memcg: move charges of anonymous swap
This patch is another core part of this move-charge-at-task-migration
feature.  It enables moving charges of anonymous swaps.

To move the charge of swap, we need to exchange swap_cgroup's record.

In current implementation, swap_cgroup's record is protected by:

  - page lock: if the entry is on swap cache.
  - swap_lock: if the entry is not on swap cache.

This works well in usual swap-in/out activity.

But this behavior make the feature of moving swap charge check many
conditions to exchange swap_cgroup's record safely.

So I changed modification of swap_cgroup's recored(swap_cgroup_record())
to use xchg, and define a new function to cmpxchg swap_cgroup's record.

This patch also enables moving charge of non pte_present but not uncharged
swap caches, which can be exist on swap-out path, by getting the target
pages via find_get_page() as do_mincore() does.

[kosaki.motohiro@jp.fujitsu.com: fix ia64 build]
[akpm@linux-foundation.org: fix typos]
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:36 -08:00

485 lines
11 KiB
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>
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);
}
} 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;
}
if (ret)
ret = notifier_from_errno(ret);
else
ret = NOTIFY_OK;
return 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;
};
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;
ctrl = &swap_cgroup_ctrl[type];
mappage = ctrl->map[idx];
sc = page_address(mappage);
sc += pos;
if (cmpxchg(&sc->id, old, new) == old)
return old;
else
return 0;
}
/**
* 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;
ctrl = &swap_cgroup_ctrl[type];
mappage = ctrl->map[idx];
sc = page_address(mappage);
sc += pos;
old = xchg(&sc->id, id);
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;
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