[PATCH 9/13] memcg: lookup page cgroup (and remove pointer from struct page)

KAMEZAWA Hiroyuki
2008-09-22T11:12:06Z

Remove page_cgroup pointer from struct page.

This patch removes page_cgroup pointer from struct page and make it be able
to get from pfn. Then, relationship of them is

Before this:
pfn <-> struct page <-> struct page_cgroup.
After this:
struct page <-> pfn -> struct page_cgroup -> struct page.

Benefit of this approach is we can remove 8 bytes from struct page.

Other changes are:
- lock/unlock_page_cgroup() uses its own bit on struct page_cgroup.
- all necessary page_cgroups are allocated at boot.

Characteristics:
- page cgroup is allocated as some amount of chunk.
This patch uses SECTION_SIZE as size of chunk if 64bit/SPARSEMEM is enabled.
If not, appropriate default number is selected.
- all page_cgroup struct is maintained by hash.
I think we have 2 ways to handle sparse index in general
...radix-tree and hash. This uses hash because radix-tree's layout is
affected by memory map's layout.
- page_cgroup.h/page_cgroup.c is added.

Changelog: v3 -> v4.
- changed arguments to lookup_page_cgroup() from "pfn" to "page",

Changelog: v2 -> v3
- changed arguments from pfn to struct page*.
- added memory hotplug callback (no undo...needs .more work.)
- adjusted to new mmotm.

Changelog: v1 -> v2
- Fixed memory allocation failure at boot to do panic with good message.
- rewrote charge/uncharge path (no changes in logic.)

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

include/linux/mm_types.h | 4
include/linux/page_cgroup.h | 89 +++++++++++++++
mm/Makefile | 2
mm/memcontrol.c | 251 +++++++++++---------------------------------
mm/page_alloc.c | 9 -
mm/page_cgroup.c | 235 +++++++++++++++++++++++++++++++++++++++++
6 files changed, 394 insertions(+), 196 deletions(-)

Index: mmotm-2.6.27-rc6+/mm/page_cgroup.c
===================================================================
--- /dev/null
+++ mmotm-2.6.27-rc6+/mm/page_cgroup.c
@@ -0,0 +1,235 @@
+#include <linux/mm.h>
+#include <linux/rcupdate.h>
+#include <linux/rculist.h>
+#include <linux/bootmem.h>
+#include <linux/bit_spinlock.h>
+#include <linux/page_cgroup.h>
+#include <linux/hash.h>
+#include <linux/memory.h>
+
+
+
+struct pcg_hash_head {
+ spinlock_t lock;
+ struct hlist_head head;
+};
+
+static struct pcg_hash_head *pcg_hashtable __read_mostly;
+
+struct pcg_hash {
+ struct hlist_node node;
+ unsigned long index;
+ struct page_cgroup *map;
+};
+
+#if BITS_PER_LONG == 32 /* we use kmalloc() */
+#define ENTS_PER_CHUNK_SHIFT (7)
+const bool chunk_vmalloc = false;
+#else /* we'll use vmalloc */
+#ifdef SECTION_SIZE_BITS
+#define ENTS_PER_CHUNK_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
+#else
+#define ENTS_PER_CHUNK_SHIFT (14) /* covers 128MB on x86-64 */
+#endif
+const bool chunk_vmalloc = true;
+#endif
+
+#define ENTS_PER_CHUNK (1 << (ENTS_PER_CHUNK_SHIFT))
+#define ENTS_PER_CHUNK_MASK (ENTS_PER_CHUNK - 1)
+
+static int pcg_hashshift __read_mostly;
+static int pcg_hashmask __read_mostly;
+
+#define PCG_HASHSHIFT (pcg_hashshift)
+#define PCG_HASHMASK (pcg_hashmask)
+#define PCG_HASHSIZE (1 << pcg_hashshift)
+
+static int pcg_hashfun(unsigned long index)
+{
+ return hash_long(index, pcg_hashshift);
+}
+
+struct page_cgroup *lookup_page_cgroup(unsigned long pfn)
+{
+ unsigned long index = pfn >> ENTS_PER_CHUNK_SHIFT;
+ struct pcg_hash *ent;
+ struct pcg_hash_head *head;
+ struct hlist_node *node;
+ struct page_cgroup *pc = NULL;
+ int hnum;
+
+ hnum = pcg_hashfun(index);
+ head = pcg_hashtable + hnum;
+ rcu_read_lock();
+ hlist_for_each_entry(ent, node, &head->head, node) {
+ if (ent->index == index) {
+ pc = ent->map + pfn;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ return pc;
+}
+
+static int __meminit alloc_page_cgroup(int node, unsigned long index)
+{
+ struct pcg_hash *ent;
+ struct pcg_hash_head *head;
+ struct page_cgroup *pc;
+ unsigned long flags, base;
+ int hnum, i;
+ int mapsize = sizeof(struct page_cgroup) * ENTS_PER_CHUNK;
+
+ if (lookup_page_cgroup(index << ENTS_PER_CHUNK_SHIFT))
+ return 0;
+
+ if (!chunk_vmalloc) {
+ int ent_size = sizeof(*ent) + mapsize;
+ ent = kmalloc_node(ent_size, GFP_KERNEL, node);
+ if (!ent)
+ return 1;
+ pc = (void *)(ent + 1);
+ } else {
+ ent = kmalloc_node(sizeof(*ent), GFP_KERNEL, node);
+ if (!ent)
+ return 1;
+ pc = vmalloc_node(mapsize, node);
+ if (!pc) {
+ kfree(ent);
+ return 1;
+ }
+ }
+ ent->map = pc - (index << ENTS_PER_CHUNK_SHIFT);
+ ent->index = index;
+ INIT_HLIST_NODE(&ent->node);
+
+ for (base = index << ENTS_PER_CHUNK_SHIFT, i = 0;
+ i < ENTS_PER_CHUNK; i++) {
+ unsigned long pfn = base + i;
+ pc = ent->map + pfn;
+ pc->page = pfn_to_page(pfn);
+ pc->mem_cgroup = NULL;
+ pc->flags = 0;
+ }
+
+ hnum = pcg_hashfun(index);
+ head = &pcg_hashtable[hnum];
+ spin_lock_irqsave(&head->lock, flags);
+ hlist_add_head_rcu(&ent->node, &head->head);
+ spin_unlock_irqrestore(&head->lock, flags);
+ return 0;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+
+int online_page_cgroup(unsigned long start_pfn,
+ unsigned long nr_pages,
+ int nid)
+{
+ unsigned long index, end_pfn, start, end;
+ int fail = 0;
+
+ end_pfn = start_pfn + nr_pages;
+ start = start_pfn >> ENTS_PER_CHUNK_SHIFT;
+ end = (end_pfn + ENTS_PER_CHUNK - 1) >> ENTS_PER_CHUNK_SHIFT;
+
+ for (index = start; (!fail) && (index < end); index++) {
+ unsigned long pfn = index << ENTS_PER_CHUNK_SHIFT;
+ if (lookup_page_cgroup(pfn))
+ continue;
+ fail = alloc_page_cgroup(nid, index);
+ }
+ return fail;
+}
+
+static int pcg_memory_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_GOING_OFFLINE:
+ break;
+ case MEM_CANCEL_ONLINE:
+ case MEM_OFFLINE:
+ case MEM_ONLINE:
+ case MEM_CANCEL_OFFLINE:
+ break;
+ }
+ ret = notifier_from_errno(ret);
+ return ret;
+}
+
+#endif
+
+/* Called From mem_cgroup's initilization */
+void __init page_cgroup_init(void)
+{
+ struct pcg_hash_head *head;
+ int node, i, fail;
+ unsigned long start, pfn, end, index, offset;
+ long default_pcg_hash_size;
+
+ /* we don't need too large hash */
+ default_pcg_hash_size = (max_pfn/ENTS_PER_CHUNK);
+ default_pcg_hash_size *= 2;
+ /* if too big, use automatic calclation */
+ if (default_pcg_hash_size > 1024 * 1024)
+ default_pcg_hash_size = 0;
+
+ pcg_hashtable = alloc_large_system_hash("PageCgroup Hash",
+ sizeof(struct pcg_hash_head),
+ default_pcg_hash_size,
+ 13,
+ 0,
+ &pcg_hashshift,
+ &pcg_hashmask,
+ 0);
+ if (!pcg_hashtable) {
+ fail = 1;
+ goto nomem;
+ }
+
+ for (i = 0; i < PCG_HASHSIZE; i++) {
+ head = &pcg_hashtable[i];
+ spin_lock_init(&head->lock);
+ INIT_HLIST_HEAD(&head->head);
+ }
+
+ fail = 0;
+ for_each_node(node) {
+ start = NODE_DATA(node)->node_start_pfn;
+ end = start + NODE_DATA(node)->node_spanned_pages;
+ start >>= ENTS_PER_CHUNK_SHIFT;
+ end = (end + ENTS_PER_CHUNK - 1) >> ENTS_PER_CHUNK_SHIFT;
+ for (index = start; (!fail) && (index < end); index++) {
+ pfn = index << ENTS_PER_CHUNK_SHIFT;
+ /*
+ * In usual, this loop breaks at offset=0.
+ * Handle a case a hole in MAX_ORDER (ia64 only...)
+ */
+ for (offset = 0; offset < ENTS_PER_CHUNK; offset++) {
+ if (pfn_valid(pfn + offset)) {
+ fail = alloc_page_cgroup(node, index);
+ break;
+ }
+ }
+ }
+ if (fail)
+ break;
+ }
+
+ hotplug_memory_notifier(pcg_memory_callback, 0);
+nomem:
+ if (fail) {
+ printk("Not enough memory for memory resource controller.\n");
+ panic("please try cgroup_disable=memory boot option.");
+ }
+ return;
+}
+
+
Index: mmotm-2.6.27-rc6+/include/linux/mm_types.h
===================================================================
--- mmotm-2.6.27-rc6+.orig/include/linux/mm_types.h
+++ mmotm-2.6.27-rc6+/include/linux/mm_types.h
@@ -94,10 +94,6 @@ struct page {
void *virtual; /* Kernel virtual address (NULL if
not kmapped, ie. highmem) */
#endif /* WANT_PAGE_VIRTUAL */
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- unsigned long page_cgroup;
-#endif
-
#ifdef CONFIG_KMEMCHECK
void *shadow;
#endif
Index: mmotm-2.6.27-rc6+/mm/Makefile
===================================================================
--- mmotm-2.6.27-rc6+.orig/mm/Makefile
+++ mmotm-2.6.27-rc6+/mm/Makefile
@@ -34,6 +34,6 @@ obj-$(CONFIG_FS_XIP) += filemap_xip.o
obj-$(CONFIG_MIGRATION) += migrate.o
obj-$(CONFIG_SMP) += allocpercpu.o
obj-$(CONFIG_QUICKLIST) += quicklist.o
-obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o
+obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o
obj-$(CONFIG_CGROUP_MEMRLIMIT_CTLR) += memrlimitcgroup.o
obj-$(CONFIG_KMEMTRACE) += kmemtrace.o
Index: mmotm-2.6.27-rc6+/include/linux/page_cgroup.h
===================================================================
--- /dev/null
+++ mmotm-2.6.27-rc6+/include/linux/page_cgroup.h
@@ -0,0 +1,89 @@
+#ifndef __LINUX_PAGE_CGROUP_H
+#define __LINUX_PAGE_CGROUP_H
+
+/*
+ * Page Cgroup can be considered as an extended mem_map.
+ * A page_cgroup page is associated with every page descriptor. The
+ * page_cgroup helps us identify information about the cgroup
+ * All page cgroups are allocated at boot or memory hotplug event,
+ * then the page cgroup for pfn always exists.
+ */
+struct page_cgroup {
+ unsigned long flags;
+ struct mem_cgroup *mem_cgroup;
+ struct page *page;
+ struct list_head lru; /* per cgroup LRU list */
+};
+
+void __init page_cgroup_init(void);
+struct page_cgroup *lookup_page_cgroup(unsigned long pfn);
+
+enum {
+ /* flags for mem_cgroup */
+ PCG_LOCK, /* page cgroup is locked */
+ PCG_CACHE, /* charged as cache */
+ PCG_USED, /* this object is in use. */
+ /* flags for LRU placement */
+ PCG_ACTIVE, /* page is active in this cgroup */
+ PCG_FILE, /* page is file system backed */
+ PCG_UNEVICTABLE, /* page is unevictableable */
+};
+
+#define TESTPCGFLAG(uname, lname) \
+static inline int PageCgroup##uname(struct page_cgroup *pc) \
+ { return test_bit(PCG_##lname, &pc->flags); }
+
+#define SETPCGFLAG(uname, lname) \
+static inline void SetPageCgroup##uname(struct page_cgroup *pc)\
+ { set_bit(PCG_##lname, &pc->flags); }
+
+#define CLEARPCGFLAG(uname, lname) \
+static inline void ClearPageCgroup##uname(struct page_cgroup *pc) \
+ { clear_bit(PCG_##lname, &pc->flags); }
+
+/* Cache flag is set only once (at allocation) */
+TESTPCGFLAG(Cache, CACHE)
+
+TESTPCGFLAG(Used, USED)
+CLEARPCGFLAG(Used, USED)
+
+/* LRU management flags (from global-lru definition) */
+TESTPCGFLAG(File, FILE)
+SETPCGFLAG(File, FILE)
+CLEARPCGFLAG(File, FILE)
+
+TESTPCGFLAG(Active, ACTIVE)
+SETPCGFLAG(Active, ACTIVE)
+CLEARPCGFLAG(Active, ACTIVE)
+
+TESTPCGFLAG(Unevictable, UNEVICTABLE)
+SETPCGFLAG(Unevictable, UNEVICTABLE)
+CLEARPCGFLAG(Unevictable, UNEVICTABLE)
+
+static inline int page_cgroup_nid(struct page_cgroup *pc)
+{
+ return page_to_nid(pc->page);
+}
+
+static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc)
+{
+ return page_zonenum(pc->page);
+}
+
+static inline void lock_page_cgroup(struct page_cgroup *pc)
+{
+ bit_spin_lock(PCG_LOCK, &pc->flags);
+}
+
+static inline int trylock_page_cgroup(struct page_cgroup *pc)
+{
+ return bit_spin_trylock(PCG_LOCK, &pc->flags);
+}
+
+static inline void unlock_page_cgroup(struct page_cgroup *pc)
+{
+ bit_spin_unlock(PCG_LOCK, &pc->flags);
+}
+
+
+#endif
Index: mmotm-2.6.27-rc6+/mm/memcontrol.c
===================================================================
--- mmotm-2.6.27-rc6+.orig/mm/memcontrol.c
+++ mmotm-2.6.27-rc6+/mm/memcontrol.c
@@ -34,11 +34,11 @@
#include <linux/seq_file.h>
#include <linux/vmalloc.h>
#include <linux/mm_inline.h>
+#include <linux/page_cgroup.h>

#include <asm/uaccess.h>

struct cgroup_subsys mem_cgroup_subsys __read_mostly;
-static struct kmem_cache *page_cgroup_cache __read_mostly;
#define MEM_CGROUP_RECLAIM_RETRIES 5

/*
@@ -138,80 +138,6 @@ static struct mem_cgroup init_mem_cgroup

#define is_root_cgroup(cgrp) ((cgrp) == &init_mem_cgroup)

-
-/*
- * We use the lower bit of the page->page_cgroup pointer as a bit spin
- * lock. We need to ensure that page->page_cgroup is at least two
- * byte aligned (based on comments from Nick Piggin). But since
- * bit_spin_lock doesn't actually set that lock bit in a non-debug
- * uniprocessor kernel, we should avoid setting it here too.
- */
-#define PAGE_CGROUP_LOCK_BIT 0x0
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-#define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT)
-#else
-#define PAGE_CGROUP_LOCK 0x0
-#endif
-
-/*
- * A page_cgroup page is associated with every page descriptor. The
- * page_cgroup helps us identify information about the cgroup
- */
-struct page_cgroup {
- struct list_head lru; /* per cgroup LRU list */
- struct page *page;
- struct mem_cgroup *mem_cgroup;
- unsigned long flags;
-};
-
-enum {
- /* flags for mem_cgroup */
- PCG_CACHE, /* charged as cache */
- /* flags for LRU placement */
- PCG_ACTIVE, /* page is active in this cgroup */
- PCG_FILE, /* page is file system backed */
- PCG_UNEVICTABLE, /* page is unevictableable */
-};
-
-#define TESTPCGFLAG(uname, lname) \
-static inline int PageCgroup##uname(struct page_cgroup *pc) \
- { return test_bit(PCG_##lname, &pc->flags); }
-
-#define SETPCGFLAG(uname, lname) \
-static inline void SetPageCgroup##uname(struct page_cgroup *pc)\
- { set_bit(PCG_##lname, &pc->flags); }
-
-#define CLEARPCGFLAG(uname, lname) \
-static inline void ClearPageCgroup##uname(struct page_cgroup *pc) \
- { clear_bit(PCG_##lname, &pc->flags); }
-
-
-/* Cache flag is set only once (at allocation) */
-TESTPCGFLAG(Cache, CACHE)
-
-/* LRU management flags (from global-lru definition) */
-TESTPCGFLAG(File, FILE)
-SETPCGFLAG(File, FILE)
-CLEARPCGFLAG(File, FILE)
-
-TESTPCGFLAG(Active, ACTIVE)
-SETPCGFLAG(Active, ACTIVE)
-CLEARPCGFLAG(Active, ACTIVE)
-
-TESTPCGFLAG(Unevictable, UNEVICTABLE)
-SETPCGFLAG(Unevictable, UNEVICTABLE)
-CLEARPCGFLAG(Unevictable, UNEVICTABLE)
-
-static int page_cgroup_nid(struct page_cgroup *pc)
-{
- return page_to_nid(pc->page);
-}
-
-static enum zone_type page_cgroup_zid(struct page_cgroup *pc)
-{
- return page_zonenum(pc->page);
-}
-
enum charge_type {
MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
MEM_CGROUP_CHARGE_TYPE_MAPPED,
@@ -222,9 +148,9 @@ enum charge_type {

static const unsigned long
pcg_default_flags[NR_CHARGE_TYPE] = {
- ((1 << PCG_CACHE) | (1 << PCG_FILE)),
- ((1 << PCG_ACTIVE)),
- ((1 << PCG_ACTIVE) | (1 << PCG_CACHE)),
+ (1 << PCG_CACHE) | (1 << PCG_FILE) | (1 << PCG_USED) | (1 << PCG_LOCK),
+ (1 << PCG_ACTIVE) | (1 << PCG_LOCK) | (1 << PCG_USED),
+ (1 << PCG_ACTIVE) | (1 << PCG_CACHE) | (1 << PCG_USED)| (1 << PCG_LOCK),
0,
};

@@ -307,37 +233,6 @@ struct mem_cgroup *mem_cgroup_from_task(
struct mem_cgroup, css);
}

-static inline int page_cgroup_locked(struct page *page)
-{
- return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
-}
-
-static void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc)
-{
- VM_BUG_ON(!page_cgroup_locked(page));
- page->page_cgroup = ((unsigned long)pc | PAGE_CGROUP_LOCK);
-}
-
-struct page_cgroup *page_get_page_cgroup(struct page *page)
-{
- return (struct page_cgroup *) (page->page_cgroup & ~PAGE_CGROUP_LOCK);
-}
-
-static void lock_page_cgroup(struct page *page)
-{
- bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
-}
-
-static int try_lock_page_cgroup(struct page *page)
-{
- return bit_spin_trylock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
-}
-
-static void unlock_page_cgroup(struct page *page)
-{
- bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
-}
-
static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone *mz,
struct page_cgroup *pc)
{
@@ -441,22 +336,19 @@ void mem_cgroup_move_lists(struct page *
* safely get to page_cgroup without it, so just try_lock it:
* mem_cgroup_isolate_pages allows for page left on wrong list.
*/
- if (!try_lock_page_cgroup(page))
+ pc = lookup_page_cgroup(page_to_pfn(page));
+
+ if (!trylock_page_cgroup(pc))
return;

- pc = page_get_page_cgroup(page);
- if (pc) {
+ if (PageCgroupUsed(pc)) {
mem = pc->mem_cgroup;
mz = page_cgroup_zoneinfo(pc);
spin_lock_irqsave(&mz->lru_lock, flags);
- /*
- * check against the race with move_account.
- */
- if (likely(mem == pc->mem_cgroup))
- __mem_cgroup_move_lists(pc, lru);
+ __mem_cgroup_move_lists(pc, lru);
spin_unlock_irqrestore(&mz->lru_lock, flags);
}
- unlock_page_cgroup(page);
+ unlock_page_cgroup(pc);
}

/*
@@ -543,6 +435,8 @@ unsigned long mem_cgroup_isolate_pages(u
list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
if (scan >= nr_to_scan)
break;
+ if (unlikely(!PageCgroupUsed(pc)))
+ continue;
page = pc->page;

if (unlikely(!PageLRU(page)))
@@ -611,12 +505,12 @@ int mem_cgroup_move_account(struct page
/* Now, we assume no_limit...no failure here. */
return ret;
}
- if (!try_lock_page_cgroup(page)) {
+ if (!trylock_page_cgroup(pc)) {
res_counter_uncharge(&to->res, PAGE_SIZE);
return ret;
}

- if (page_get_page_cgroup(page) != pc) {
+ if (!PageCgroupUsed(pc)) {
res_counter_uncharge(&to->res, PAGE_SIZE);
goto out;
}
@@ -634,7 +528,7 @@ int mem_cgroup_move_account(struct page
res_counter_uncharge(&to->res, PAGE_SIZE);
}
out:
- unlock_page_cgroup(page);
+ unlock_page_cgroup(pc);

return ret;
}
@@ -651,26 +545,27 @@ static int mem_cgroup_charge_common(stru
{
struct mem_cgroup *mem;
struct page_cgroup *pc;
- unsigned long flags;
unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
struct mem_cgroup_per_zone *mz;
+ unsigned long flags;

- pc = kmem_cache_alloc(page_cgroup_cache, gfp_mask);
- if (unlikely(pc == NULL))
- goto err;
-
+ pc = lookup_page_cgroup(page_to_pfn(page));
+ /* can happen at boot */
+ if (unlikely(!pc))
+ return 0;
+ prefetchw(pc);
/*
* We always charge the cgroup the mm_struct belongs to.
* The mm_struct's mem_cgroup changes on task migration if the
* thread group leader migrates. It's possible that mm is not
* set, if so charge the init_mm (happens for pagecache usage).
*/
+
if (likely(!memcg)) {
rcu_read_lock();
mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
if (unlikely(!mem)) {
rcu_read_unlock();
- kmem_cache_free(page_cgroup_cache, pc);
return 0;
}
/*
@@ -706,36 +601,34 @@ static int mem_cgroup_charge_common(stru
}
}

+ preempt_disable();
+ lock_page_cgroup(pc);
+ if (unlikely(PageCgroupUsed(pc))) {
+ unlock_page_cgroup(pc);
+ res_counter_uncharge(&mem->res, PAGE_SIZE);
+ css_put(&mem->css);
+ preempt_enable();
+ goto done;
+ }
pc->mem_cgroup = mem;
- pc->page = page;
/*
* If a page is accounted as a page cache, insert to inactive list.
* If anon, insert to active list.
*/
pc->flags = pcg_default_flags[ctype];

- lock_page_cgroup(page);
- if (unlikely(page_get_page_cgroup(page))) {
- unlock_page_cgroup(page);
- res_counter_uncharge(&mem->res, PAGE_SIZE);
- css_put(&mem->css);
- kmem_cache_free(page_cgroup_cache, pc);
- goto done;
- }
- page_assign_page_cgroup(page, pc);
-
mz = page_cgroup_zoneinfo(pc);
+
spin_lock_irqsave(&mz->lru_lock, flags);
__mem_cgroup_add_list(mz, pc);
spin_unlock_irqrestore(&mz->lru_lock, flags);
+ unlock_page_cgroup(pc);
+ preempt_enable();

- unlock_page_cgroup(page);
done:
return 0;
out:
css_put(&mem->css);
- kmem_cache_free(page_cgroup_cache, pc);
-err:
return -ENOMEM;
}

@@ -743,7 +636,8 @@ int mem_cgroup_charge(struct page *page,
{
if (mem_cgroup_subsys.disabled)
return 0;
-
+ if (PageCompound(page))
+ return 0;
/*
* If already mapped, we don't have to account.
* If page cache, page->mapping has address_space.
@@ -764,7 +658,8 @@ int mem_cgroup_cache_charge(struct page
{
if (mem_cgroup_subsys.disabled)
return 0;
-
+ if (PageCompound(page))
+ return 0;
/*
* Corner case handling. This is called from add_to_page_cache()
* in usual. But some FS (shmem) precharges this page before calling it
@@ -777,15 +672,16 @@ int mem_cgroup_cache_charge(struct page
if (!(gfp_mask & __GFP_WAIT)) {
struct page_cgroup *pc;

- lock_page_cgroup(page);
- pc = page_get_page_cgroup(page);
- if (pc) {
- VM_BUG_ON(pc->page != page);
- VM_BUG_ON(!pc->mem_cgroup);
- unlock_page_cgroup(page);
+
+ pc = lookup_page_cgroup(page_to_pfn(page));
+ if (!pc)
+ return 0;
+ lock_page_cgroup(pc);
+ if (PageCgroupUsed(pc)) {
+ unlock_page_cgroup(pc);
return 0;
}
- unlock_page_cgroup(page);
+ unlock_page_cgroup(pc);
}

if (unlikely(!mm))
@@ -808,53 +704,46 @@ __mem_cgroup_uncharge_common(struct page
struct page_cgroup *pc;
struct mem_cgroup *mem;
struct mem_cgroup_per_zone *mz;
+ unsigned long pfn = page_to_pfn(page);
unsigned long flags;

if (mem_cgroup_subsys.disabled)
return;
+ /* check the condition we can know from page */

- /*
- * Check if our page_cgroup is valid
- */
- lock_page_cgroup(page);
- pc = page_get_page_cgroup(page);
- if (unlikely(!pc))
- goto unlock;
-
- VM_BUG_ON(pc->page != page);
+ pc = lookup_page_cgroup(pfn);
+ if (unlikely(!pc || !PageCgroupUsed(pc)))
+ return;
+ preempt_disable();
+ lock_page_cgroup(pc);
+ if (unlikely(page_mapped(page))) {
+ unlock_page_cgroup(pc);
+ preempt_enable();
+ return;
+ }
+ ClearPageCgroupUsed(pc);
+ unlock_page_cgroup(pc);

- if ((ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
- && ((PageCgroupCache(pc) || page_mapped(page))))
- goto unlock;
-retry:
mem = pc->mem_cgroup;
mz = page_cgroup_zoneinfo(pc);
+
spin_lock_irqsave(&mz->lru_lock, flags);
- if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED &&
- unlikely(mem != pc->mem_cgroup)) {
- /* MAPPED account can be done without lock_page().
- Check race with mem_cgroup_move_account() */
- spin_unlock_irqrestore(&mz->lru_lock, flags);
- goto retry;
- }
__mem_cgroup_remove_list(mz, pc);
spin_unlock_irqrestore(&mz->lru_lock, flags);
-
- page_assign_page_cgroup(page, NULL);
- unlock_page_cgroup(page);
-
-
- res_counter_uncharge(&mem->res, PAGE_SIZE);
+ pc->mem_cgroup = NULL;
css_put(&mem->css);
+ preempt_enable();
+ res_counter_uncharge(&mem->res, PAGE_SIZE);

- kmem_cache_free(page_cgroup_cache, pc);
return;
-unlock:
- unlock_page_cgroup(page);
}

void mem_cgroup_uncharge_page(struct page *page)
{
+ if (page_mapped(page))
+ return;
+ if (page->mapping && !PageAnon(page))
+ return;
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
}

@@ -878,9 +767,9 @@ int mem_cgroup_prepare_migration(struct
if (mem_cgroup_subsys.disabled)
return 0;

- lock_page_cgroup(page);
- pc = page_get_page_cgroup(page);
- if (pc) {
+ pc = lookup_page_cgroup(page_to_pfn(page));
+ lock_page_cgroup(pc);
+ if (PageCgroupUsed(pc)) {
mem = pc->mem_cgroup;
css_get(&mem->css);
if (PageCgroupCache(pc)) {
@@ -890,7 +779,7 @@ int mem_cgroup_prepare_migration(struct
ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
}
}
- unlock_page_cgroup(page);
+ unlock_page_cgroup(pc);
if (mem) {
ret = mem_cgroup_charge_common(newpage, NULL, GFP_KERNEL,
ctype, mem);
@@ -1271,8 +1160,8 @@ mem_cgroup_create(struct cgroup_subsys *
int node;

if (unlikely((cont->parent) == NULL)) {
+ page_cgroup_init();
mem = &init_mem_cgroup;
- page_cgroup_cache = KMEM_CACHE(page_cgroup, SLAB_PANIC);
} else {
mem = mem_cgroup_alloc();
if (!mem)
Index: mmotm-2.6.27-rc6+/mm/page_alloc.c
===================================================================
--- mmotm-2.6.27-rc6+.orig/mm/page_alloc.c
+++ mmotm-2.6.27-rc6+/mm/page_alloc.c
@@ -223,17 +223,12 @@ static inline int bad_range(struct zone

static void bad_page(struct page *page)
{
- void *pc = page_get_page_cgroup(page);
-
printk(KERN_EMERG "Bad page state in process '%s'\n" KERN_EMERG
"page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
current->comm, page, (int)(2*sizeof(unsigned long)),
(unsigned long)page->flags, page->mapping,
page_mapcount(page), page_count(page));
- if (pc) {
- printk(KERN_EMERG "cgroup:%p\n", pc);
- page_reset_bad_cgroup(page);
- }
+
printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
KERN_EMERG "Backtrace:\n");
dump_stack();
@@ -472,7 +467,6 @@ static inline void free_pages_check(stru
free_page_mlock(page);
if (unlikely(page_mapcount(page) |
(page->mapping != NULL) |
- (page_get_page_cgroup(page) != NULL) |
(page_count(page) != 0) |
(page->flags & PAGE_FLAGS_CHECK_AT_FREE)))
bad_page(page);
@@ -609,7 +603,6 @@ static void prep_new_page(struct page *p
{
if (unlikely(page_mapcount(page) |
(page->mapping != NULL) |
- (page_get_page_cgroup(page) != NULL) |
(page_count(page) != 0) |
(page->flags & PAGE_FLAGS_CHECK_AT_PREP)))
bad_page(page);