[RFC][PATCH 6/6] memcg: synchronized LRU

From: KAMEZAWA Hiroyuki
Date: Tue Nov 11 2008 - 22:32:53 EST


A patch for changing memcg's LRU semantics.

Now,
- page_cgroup is linked to mem_cgroup's its own LRU (per zone).

- LRU of page_cgroup is not synchronous with global LRU.

- page and page_cgroup is one-to-one and statically allocated.

- To find page_cgroup is on what LRU, you have to check pc->mem_cgroup as
- lru = page_cgroup_zoneinfo(pc, nid_of_pc, zid_of_pc);

- SwapCache is handled.

And, when we handle LRU list of page_cgroup, we do following.

pc = lookup_page_cgroup(page);
lock_page_cgroup(pc); .....................(1)
mz = page_cgroup_zoneinfo(pc);
spin_lock(&mz->lru_lock);
.....add to LRU
spin_unlock(&mz->lru_lock);
unlock_page_cgroup(pc);

But (1) is spin_lock and we have to be afraid of dead-lock with zone->lru_lock.
So, trylock() is used at (1), now. Without (1), we can't trust "mz" is correct.

This is a trial to remove this dirty nesting of locks.
This patch changes mz->lru_lock to be zone->lru_lock.
Then, above sequence will be written as

spin_lock(&zone->lru_lock); # in vmscan.c or swap.c via global LRU
mem_cgroup_add/remove/etc_lru() {
pc = lookup_page_cgroup(page);
mz = page_cgroup_zoneinfo(pc);
if (PageCgroupUsed(pc)) {
....add to LRU
}
spin_lock(&zone->lru_lock); # in vmscan.c or swap.c via global LRU

This is much simpler.
(*) We're safe even if we don't take lock_page_cgroup(pc). Because..
1. When pc->mem_cgroup can be modified.
- at charge.
- at account_move().
2. at charge
the PCG_USED bit is not set before pc->mem_cgroup is fixed.
3. at account_move()
the page is isolated and not on LRU.

Pros.
- easy for maintenance.
- memcg can make use of laziness of pagevec.
- we don't have to duplicated LRU/Active/Unevictable bit in page_cgroup.
- LRU status of memcg will be synchronized with global LRU's one.
- # of locks are reduced.
- account_move() is simplified very much.
Cons.
- may increase cost of LRU rotation.
(no impact if memcg is not configured.)

Changelog v0 -> v1
- fixed statistics.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>

fs/splice.c | 1
include/linux/memcontrol.h | 29 +++
include/linux/mm_inline.h | 3
include/linux/page_cgroup.h | 17 --
mm/memcontrol.c | 332 +++++++++++++++++++-------------------------
mm/page_cgroup.c | 1
mm/swap.c | 1
mm/vmscan.c | 9 -
8 files changed, 183 insertions(+), 210 deletions(-)

Index: mmotm-2.6.28-Nov10/mm/memcontrol.c
===================================================================
--- mmotm-2.6.28-Nov10.orig/mm/memcontrol.c
+++ mmotm-2.6.28-Nov10/mm/memcontrol.c
@@ -36,6 +36,7 @@
#include <linux/vmalloc.h>
#include <linux/mm_inline.h>
#include <linux/page_cgroup.h>
+#include "internal.h"

#include <asm/uaccess.h>

@@ -100,7 +101,6 @@ struct mem_cgroup_per_zone {
/*
* spin_lock to protect the per cgroup LRU
*/
- spinlock_t lru_lock;
struct list_head lists[NR_LRU_LISTS];
unsigned long count[NR_LRU_LISTS];
};
@@ -137,6 +137,11 @@ struct mem_cgroup {
*/
struct res_counter memsw;
/*
+ * Statistics.
+ */
+ struct mem_cgroup_stat stat;
+ /*
+ * Below is read-mostly part.
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
*/
@@ -144,10 +149,6 @@ struct mem_cgroup {

int prev_priority; /* for recording reclaim priority */
/*
- * statistics.
- */
- struct mem_cgroup_stat stat;
- /*
* attributes.
* on_rmdir ....0=free all 1=move all.
*/
@@ -173,14 +174,12 @@ enum charge_type {
/* only for here (for easy reading.) */
#define PCGF_CACHE (1UL << PCG_CACHE)
#define PCGF_USED (1UL << PCG_USED)
-#define PCGF_ACTIVE (1UL << PCG_ACTIVE)
#define PCGF_LOCK (1UL << PCG_LOCK)
-#define PCGF_FILE (1UL << PCG_FILE)
static const unsigned long
pcg_default_flags[NR_CHARGE_TYPE] = {
- PCGF_CACHE | PCGF_FILE | PCGF_USED | PCGF_LOCK, /* File Cache */
- PCGF_ACTIVE | PCGF_USED | PCGF_LOCK, /* Anon */
- PCGF_ACTIVE | PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
+ PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */
+ PCGF_USED | PCGF_LOCK, /* Anon */
+ PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
0, /* FORCE */
};

@@ -211,9 +210,6 @@ static char *memcg_attribute_names[MEMCG
static void mem_cgroup_get(struct mem_cgroup *mem);
static void mem_cgroup_put(struct mem_cgroup *mem);

-/*
- * Always modified under lru lock. Then, not necessary to preempt_disable()
- */
static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
struct page_cgroup *pc,
bool charge)
@@ -221,10 +217,9 @@ static void mem_cgroup_charge_statistics
int val = (charge)? 1 : -1;
struct mem_cgroup_stat *stat = &mem->stat;
struct mem_cgroup_stat_cpu *cpustat;
+ int cpu = get_cpu();

- VM_BUG_ON(!irqs_disabled());
-
- cpustat = &stat->cpustat[smp_processor_id()];
+ cpustat = &stat->cpustat[cpu];
if (PageCgroupCache(pc))
__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val);
else
@@ -236,6 +231,7 @@ static void mem_cgroup_charge_statistics
else
__mem_cgroup_stat_add_safe(cpustat,
MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
+ put_cpu();
}

static struct mem_cgroup_per_zone *
@@ -290,80 +286,95 @@ struct mem_cgroup *mem_cgroup_from_task(
struct mem_cgroup, css);
}

-static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone *mz,
- struct page_cgroup *pc)
-{
- int lru = LRU_BASE;
+/*
+ * Following LRU functions are allowed to be used without PCG_LOCK.
+ * Operations are called by routine of global LRU independently from memcg.
+ * What we have to take care of here is validness of pc->mem_cgroup.
+ *
+ * Changes to pc->mem_cgroup happens when
+ * 1. charge
+ * 2. moving account
+ * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
+ * It is added to LRU before charge.
+ * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
+ * When moving account, the page is not on LRU. It's isolated.
+ */

- if (PageCgroupUnevictable(pc))
- lru = LRU_UNEVICTABLE;
- else {
- if (PageCgroupActive(pc))
- lru += LRU_ACTIVE;
- if (PageCgroupFile(pc))
- lru += LRU_FILE;
- }
+void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
+{
+ struct page_cgroup *pc;
+ struct mem_cgroup *mem;
+ struct mem_cgroup_per_zone *mz;

+ if (mem_cgroup_subsys.disabled)
+ return;
+ pc = lookup_page_cgroup(page);
+ /* can happen while we handle swapcache. */
+ if (list_empty(&pc->lru))
+ return;
+ mz = page_cgroup_zoneinfo(pc);
+ mem = pc->mem_cgroup;
MEM_CGROUP_ZSTAT(mz, lru) -= 1;
-
- mem_cgroup_charge_statistics(pc->mem_cgroup, pc, false);
- list_del(&pc->lru);
+ list_del_init(&pc->lru);
+ return;
}

-static void __mem_cgroup_add_list(struct mem_cgroup_per_zone *mz,
- struct page_cgroup *pc, bool hot)
+void mem_cgroup_del_lru(struct page *page)
{
- int lru = LRU_BASE;
+ mem_cgroup_del_lru_list(page, page_lru(page));
+}

- if (PageCgroupUnevictable(pc))
- lru = LRU_UNEVICTABLE;
- else {
- if (PageCgroupActive(pc))
- lru += LRU_ACTIVE;
- if (PageCgroupFile(pc))
- lru += LRU_FILE;
- }
+void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
+{
+ struct mem_cgroup_per_zone *mz;
+ struct page_cgroup *pc;

- MEM_CGROUP_ZSTAT(mz, lru) += 1;
- if (hot)
- list_add(&pc->lru, &mz->lists[lru]);
- else
- list_add_tail(&pc->lru, &mz->lists[lru]);
+ if (mem_cgroup_subsys.disabled)
+ return;

- mem_cgroup_charge_statistics(pc->mem_cgroup, pc, true);
+ pc = lookup_page_cgroup(page);
+ smp_rmb();
+ /* unused page is not rotated. */
+ if (!PageCgroupUsed(pc))
+ return;
+ mz = page_cgroup_zoneinfo(pc);
+ list_move(&pc->lru, &mz->lists[lru]);
}

-static void __mem_cgroup_move_lists(struct page_cgroup *pc, enum lru_list lru)
+void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
{
- struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
- int active = PageCgroupActive(pc);
- int file = PageCgroupFile(pc);
- int unevictable = PageCgroupUnevictable(pc);
- enum lru_list from = unevictable ? LRU_UNEVICTABLE :
- (LRU_FILE * !!file + !!active);
+ struct page_cgroup *pc;
+ struct mem_cgroup_per_zone *mz;

- if (lru == from)
+ if (mem_cgroup_subsys.disabled)
+ return;
+ pc = lookup_page_cgroup(page);
+ /* barrier to sync with "charge" */
+ smp_rmb();
+ if (!PageCgroupUsed(pc))
return;

- MEM_CGROUP_ZSTAT(mz, from) -= 1;
- /*
- * However this is done under mz->lru_lock, another flags, which
- * are not related to LRU, will be modified from out-of-lock.
- * We have to use atomic set/clear flags.
- */
- if (is_unevictable_lru(lru)) {
- ClearPageCgroupActive(pc);
- SetPageCgroupUnevictable(pc);
- } else {
- if (is_active_lru(lru))
- SetPageCgroupActive(pc);
- else
- ClearPageCgroupActive(pc);
- ClearPageCgroupUnevictable(pc);
- }
-
+ mz = page_cgroup_zoneinfo(pc);
MEM_CGROUP_ZSTAT(mz, lru) += 1;
- list_move(&pc->lru, &mz->lists[lru]);
+ list_add(&pc->lru, &mz->lists[lru]);
+}
+/*
+ * To add swapcache into LRU. Be careful to all this function.
+ * zone->lru_lock shouldn't be held and irq must not be disabled.
+ */
+static void mem_cgroup_lru_fixup(struct page *page)
+{
+ if (!isolate_lru_page(page))
+ putback_lru_page(page);
+}
+
+void mem_cgroup_move_lists(struct page *page,
+ enum lru_list from, enum lru_list to)
+{
+ if (mem_cgroup_subsys.disabled)
+ return;
+ mem_cgroup_del_lru_list(page, from);
+ mem_cgroup_add_lru_list(page, to);
}

int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
@@ -377,37 +388,6 @@ int task_in_mem_cgroup(struct task_struc
}

/*
- * This routine assumes that the appropriate zone's lru lock is already held
- */
-void mem_cgroup_move_lists(struct page *page, enum lru_list lru)
-{
- struct page_cgroup *pc;
- struct mem_cgroup_per_zone *mz;
- unsigned long flags;
-
- if (mem_cgroup_subsys.disabled)
- return;
-
- /*
- * We cannot lock_page_cgroup while holding zone's lru_lock,
- * because other holders of lock_page_cgroup can be interrupted
- * with an attempt to rotate_reclaimable_page. But we cannot
- * safely get to page_cgroup without it, so just try_lock it:
- * mem_cgroup_isolate_pages allows for page left on wrong list.
- */
- pc = lookup_page_cgroup(page);
- if (!trylock_page_cgroup(pc))
- return;
- if (pc && PageCgroupUsed(pc)) {
- mz = page_cgroup_zoneinfo(pc);
- spin_lock_irqsave(&mz->lru_lock, flags);
- __mem_cgroup_move_lists(pc, lru);
- spin_unlock_irqrestore(&mz->lru_lock, flags);
- }
- unlock_page_cgroup(pc);
-}
-
-/*
* Calculate mapped_ratio under memory controller. This will be used in
* vmscan.c for deteremining we have to reclaim mapped pages.
*/
@@ -486,40 +466,24 @@ unsigned long mem_cgroup_isolate_pages(u
mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
src = &mz->lists[lru];

- spin_lock(&mz->lru_lock);
scan = 0;
list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
if (scan >= nr_to_scan)
break;
+
+ page = pc->page;
if (unlikely(!PageCgroupUsed(pc)))
continue;
- page = pc->page;
-
if (unlikely(!PageLRU(page)))
continue;

- /*
- * TODO: play better with lumpy reclaim, grabbing anything.
- */
- if (PageUnevictable(page) ||
- (PageActive(page) && !active) ||
- (!PageActive(page) && active)) {
- __mem_cgroup_move_lists(pc, page_lru(page));
- continue;
- }
-
scan++;
- list_move(&pc->lru, &pc_list);
-
if (__isolate_lru_page(page, mode, file) == 0) {
list_move(&page->lru, dst);
nr_taken++;
}
}

- list_splice(&pc_list, src);
- spin_unlock(&mz->lru_lock);
-
*scanned = scan;
return nr_taken;
}
@@ -634,9 +598,6 @@ static void __mem_cgroup_commit_charge(s
struct page_cgroup *pc,
enum charge_type ctype)
{
- struct mem_cgroup_per_zone *mz;
- unsigned long flags;
-
/* try_charge() can return NULL to *memcg, taking care of it. */
if (!mem)
return;
@@ -651,17 +612,11 @@ static void __mem_cgroup_commit_charge(s
return;
}
pc->mem_cgroup = mem;
- /*
- * If a page is accounted as a page cache, insert to inactive list.
- * If anon, insert to active list.
- */
+ smp_wmb();
pc->flags = pcg_default_flags[ctype];

- mz = page_cgroup_zoneinfo(pc);
+ mem_cgroup_charge_statistics(mem, pc, true);

- spin_lock_irqsave(&mz->lru_lock, flags);
- __mem_cgroup_add_list(mz, pc, true);
- spin_unlock_irqrestore(&mz->lru_lock, flags);
unlock_page_cgroup(pc);
}

@@ -672,8 +627,7 @@ static void __mem_cgroup_commit_charge(s
* @to: mem_cgroup which the page is moved to. @from != @to.
*
* The caller must confirm following.
- * 1. disable irq.
- * 2. lru_lock of old mem_cgroup(@from) should be held.
+ * - page is not on LRU (isolate_page() is useful.)
*
* returns 0 at success,
* returns -EBUSY when lock is busy or "pc" is unstable.
@@ -689,15 +643,14 @@ static int mem_cgroup_move_account(struc
int nid, zid;
int ret = -EBUSY;

- VM_BUG_ON(!irqs_disabled());
VM_BUG_ON(from == to);
+ VM_BUG_ON(PageLRU(pc->page));

nid = page_cgroup_nid(pc);
zid = page_cgroup_zid(pc);
from_mz = mem_cgroup_zoneinfo(from, nid, zid);
to_mz = mem_cgroup_zoneinfo(to, nid, zid);

-
if (!trylock_page_cgroup(pc))
return ret;

@@ -707,18 +660,15 @@ static int mem_cgroup_move_account(struc
if (pc->mem_cgroup != from)
goto out;

- if (spin_trylock(&to_mz->lru_lock)) {
- __mem_cgroup_remove_list(from_mz, pc);
- css_put(&from->css);
- res_counter_uncharge(&from->res, PAGE_SIZE);
- if (do_swap_account)
- res_counter_uncharge(&from->memsw, PAGE_SIZE);
- pc->mem_cgroup = to;
- css_get(&to->css);
- __mem_cgroup_add_list(to_mz, pc, false);
- ret = 0;
- spin_unlock(&to_mz->lru_lock);
- }
+ css_put(&from->css);
+ res_counter_uncharge(&from->res, PAGE_SIZE);
+ mem_cgroup_charge_statistics(from, pc, false);
+ if (do_swap_account)
+ res_counter_uncharge(&from->memsw, PAGE_SIZE);
+ pc->mem_cgroup = to;
+ mem_cgroup_charge_statistics(to, pc, true);
+ css_get(&to->css);
+ ret = 0;
out:
unlock_page_cgroup(pc);
return ret;
@@ -732,39 +682,47 @@ static int mem_cgroup_move_parent(struct
struct mem_cgroup *child,
gfp_t gfp_mask)
{
+ struct page *page = pc->page;
struct cgroup *cg = child->css.cgroup;
struct cgroup *pcg = cg->parent;
struct mem_cgroup *parent;
- struct mem_cgroup_per_zone *mz;
- unsigned long flags;
int ret;

/* Is ROOT ? */
if (!pcg)
return -EINVAL;

+
parent = mem_cgroup_from_cont(pcg);

+
ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
if (ret)
return ret;

- mz = mem_cgroup_zoneinfo(child,
- page_cgroup_nid(pc), page_cgroup_zid(pc));
+ if (!get_page_unless_zero(page))
+ return -EBUSY;
+
+ ret = isolate_lru_page(page);
+
+ if (ret)
+ goto cancel;

- spin_lock_irqsave(&mz->lru_lock, flags);
ret = mem_cgroup_move_account(pc, child, parent);
- spin_unlock_irqrestore(&mz->lru_lock, flags);

- /* drop extra refcnt */
+ /* drop extra refcnt by try_charge() (move_account increment one) */
css_put(&parent->css);
- /* uncharge if move fails */
- if (ret) {
- res_counter_uncharge(&parent->res, PAGE_SIZE);
- if (do_swap_account)
- res_counter_uncharge(&parent->memsw, PAGE_SIZE);
+ putback_lru_page(page);
+ if (!ret) {
+ put_page(page);
+ return 0;
}
-
+ /* uncharge if move fails */
+cancel:
+ res_counter_uncharge(&parent->res, PAGE_SIZE);
+ if (do_swap_account)
+ res_counter_uncharge(&parent->memsw, PAGE_SIZE);
+ put_page(page);
return ret;
}

@@ -930,6 +888,8 @@ int mem_cgroup_cache_charge_swapin(struc
}
if (!locked)
unlock_page(page);
+ /* add this page(page_cgroup) to the LRU we want. */
+ mem_cgroup_lru_fixup(page);

return ret;
}
@@ -962,6 +922,8 @@ void mem_cgroup_commit_charge_swapin(str
}

}
+ /* add this page(page_cgroup) to the LRU we want. */
+ mem_cgroup_lru_fixup(page);
}

void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
@@ -986,7 +948,6 @@ __mem_cgroup_uncharge_common(struct page
struct page_cgroup *pc;
struct mem_cgroup *mem = NULL;
struct mem_cgroup_per_zone *mz;
- unsigned long flags;

if (mem_cgroup_subsys.disabled)
return NULL;
@@ -1028,12 +989,10 @@ __mem_cgroup_uncharge_common(struct page
if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
res_counter_uncharge(&mem->memsw, PAGE_SIZE);

+ mem_cgroup_charge_statistics(mem, pc, false);
ClearPageCgroupUsed(pc);

mz = page_cgroup_zoneinfo(pc);
- spin_lock_irqsave(&mz->lru_lock, flags);
- __mem_cgroup_remove_list(mz, pc);
- spin_unlock_irqrestore(&mz->lru_lock, flags);
unlock_page_cgroup(pc);

css_put(&mem->css);
@@ -1287,21 +1246,22 @@ int mem_cgroup_resize_memsw_limit(struct
return ret;
}

-
/*
* This routine traverse page_cgroup in given list and drop them all.
* *And* this routine doesn't reclaim page itself, just removes page_cgroup.
*/
static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
- struct mem_cgroup_per_zone *mz,
- enum lru_list lru)
+ int node, int zid, enum lru_list lru)
{
+ struct zone *zone;
+ struct mem_cgroup_per_zone *mz;
struct page_cgroup *pc, *busy;
- unsigned long flags;
- unsigned long loop;
+ unsigned long flags, loop;
struct list_head *list;
int ret = 0;

+ zone = &NODE_DATA(node)->node_zones[zid];
+ mz = mem_cgroup_zoneinfo(mem, node, zid);
list = &mz->lists[lru];

loop = MEM_CGROUP_ZSTAT(mz, lru);
@@ -1310,19 +1270,19 @@ static int mem_cgroup_force_empty_list(s
busy = NULL;
while (loop--) {
ret = 0;
- spin_lock_irqsave(&mz->lru_lock, flags);
+ spin_lock_irqsave(&zone->lru_lock, flags);
if (list_empty(list)) {
- spin_unlock_irqrestore(&mz->lru_lock, flags);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
break;
}
pc = list_entry(list->prev, struct page_cgroup, lru);
if (busy == pc) {
list_move(&pc->lru, list);
busy = 0;
- spin_unlock_irqrestore(&mz->lru_lock, flags);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
continue;
}
- spin_unlock_irqrestore(&mz->lru_lock, flags);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);

ret = mem_cgroup_move_parent(pc, mem, GFP_HIGHUSER_MOVABLE);
if (ret == -ENOMEM)
@@ -1335,6 +1295,7 @@ static int mem_cgroup_force_empty_list(s
} else
busy = NULL;
}
+
if (!ret && !list_empty(list))
return -EBUSY;
return ret;
@@ -1370,12 +1331,10 @@ move_account:
ret = 0;
for_each_node_state(node, N_POSSIBLE) {
for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
- struct mem_cgroup_per_zone *mz;
enum lru_list l;
- mz = mem_cgroup_zoneinfo(mem, node, zid);
for_each_lru(l) {
ret = mem_cgroup_force_empty_list(mem,
- mz, l);
+ node, zid, l);
if (ret)
break;
}
@@ -1419,6 +1378,7 @@ try_to_free:
}

}
+ lru_add_drain();
/* try move_account...there may be some *locked* pages. */
if (mem->res.usage)
goto move_account;
@@ -1754,7 +1714,6 @@ static int alloc_mem_cgroup_per_zone_inf

for (zone = 0; zone < MAX_NR_ZONES; zone++) {
mz = &pn->zoneinfo[zone];
- spin_lock_init(&mz->lru_lock);
for_each_lru(l)
INIT_LIST_HEAD(&mz->lists[l]);
}
@@ -1796,8 +1755,15 @@ static struct mem_cgroup *mem_cgroup_all

static void mem_cgroup_free(struct mem_cgroup *mem)
{
+ int node;
+
if (atomic_read(&mem->refcnt) > 0)
return;
+
+
+ for_each_node_state(node, N_POSSIBLE)
+ free_mem_cgroup_per_zone_info(mem, node);
+
if (sizeof(*mem) < PAGE_SIZE)
kfree(mem);
else
@@ -1879,12 +1845,6 @@ static void mem_cgroup_pre_destroy(struc
static void mem_cgroup_destroy(struct cgroup_subsys *ss,
struct cgroup *cont)
{
- int node;
- struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
-
- for_each_node_state(node, N_POSSIBLE)
- free_mem_cgroup_per_zone_info(mem, node);
-
mem_cgroup_free(mem_cgroup_from_cont(cont));
}

Index: mmotm-2.6.28-Nov10/include/linux/memcontrol.h
===================================================================
--- mmotm-2.6.28-Nov10.orig/include/linux/memcontrol.h
+++ mmotm-2.6.28-Nov10/include/linux/memcontrol.h
@@ -40,7 +40,12 @@ extern void mem_cgroup_cancel_charge_swa

extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask);
-extern void mem_cgroup_move_lists(struct page *page, enum lru_list lru);
+extern void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru);
+extern void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru);
+extern void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru);
+extern void mem_cgroup_del_lru(struct page *page);
+extern void mem_cgroup_move_lists(struct page *page,
+ enum lru_list from, enum lru_list to);
extern void mem_cgroup_uncharge_page(struct page *page);
extern void mem_cgroup_uncharge_cache_page(struct page *page);
extern int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask);
@@ -131,7 +136,27 @@ static inline int mem_cgroup_shrink_usag
return 0;
}

-static inline void mem_cgroup_move_lists(struct page *page, bool active)
+static inline void mem_cgroup_add_lru_list(struct page *page, int lru)
+{
+}
+
+static inline void mem_cgroup_del_lru_list(struct page *page, int lru)
+{
+ return ;
+}
+
+static inline void mem_cgroup_rotate_lru_list(struct page *page, int lru)
+{
+ return ;
+}
+
+static inline void mem_cgroup_del_lru(struct page *page)
+{
+ return ;
+}
+
+static inline void
+mem_cgroup_move_lists(struct page *page, enum lru_list from, enum lru_list to)
{
}

Index: mmotm-2.6.28-Nov10/include/linux/mm_inline.h
===================================================================
--- mmotm-2.6.28-Nov10.orig/include/linux/mm_inline.h
+++ mmotm-2.6.28-Nov10/include/linux/mm_inline.h
@@ -28,6 +28,7 @@ add_page_to_lru_list(struct zone *zone,
{
list_add(&page->lru, &zone->lru[l].list);
__inc_zone_state(zone, NR_LRU_BASE + l);
+ mem_cgroup_add_lru_list(page, l);
}

static inline void
@@ -35,6 +36,7 @@ del_page_from_lru_list(struct zone *zone
{
list_del(&page->lru);
__dec_zone_state(zone, NR_LRU_BASE + l);
+ mem_cgroup_del_lru_list(page, l);
}

static inline void
@@ -54,6 +56,7 @@ del_page_from_lru(struct zone *zone, str
l += page_is_file_cache(page);
}
__dec_zone_state(zone, NR_LRU_BASE + l);
+ mem_cgroup_del_lru_list(page, l);
}

/**
Index: mmotm-2.6.28-Nov10/mm/page_cgroup.c
===================================================================
--- mmotm-2.6.28-Nov10.orig/mm/page_cgroup.c
+++ mmotm-2.6.28-Nov10/mm/page_cgroup.c
@@ -17,6 +17,7 @@ __init_page_cgroup(struct page_cgroup *p
pc->flags = 0;
pc->mem_cgroup = NULL;
pc->page = pfn_to_page(pfn);
+ INIT_LIST_HEAD(&pc->lru);
}
static unsigned long total_usage;

Index: mmotm-2.6.28-Nov10/fs/splice.c
===================================================================
--- mmotm-2.6.28-Nov10.orig/fs/splice.c
+++ mmotm-2.6.28-Nov10/fs/splice.c
@@ -21,6 +21,7 @@
#include <linux/file.h>
#include <linux/pagemap.h>
#include <linux/splice.h>
+#include <linux/memcontrol.h>
#include <linux/mm_inline.h>
#include <linux/swap.h>
#include <linux/writeback.h>
Index: mmotm-2.6.28-Nov10/mm/vmscan.c
===================================================================
--- mmotm-2.6.28-Nov10.orig/mm/vmscan.c
+++ mmotm-2.6.28-Nov10/mm/vmscan.c
@@ -565,7 +565,6 @@ redo:
lru = LRU_UNEVICTABLE;
add_page_to_unevictable_list(page);
}
- mem_cgroup_move_lists(page, lru);

/*
* page's status can change while we move it among lru. If an evictable
@@ -600,7 +599,6 @@ void putback_lru_page(struct page *page)

lru = !!TestClearPageActive(page) + page_is_file_cache(page);
lru_cache_add_lru(page, lru);
- mem_cgroup_move_lists(page, lru);
put_page(page);
}
#endif /* CONFIG_UNEVICTABLE_LRU */
@@ -872,6 +870,7 @@ int __isolate_lru_page(struct page *page
return ret;

ret = -EBUSY;
+
if (likely(get_page_unless_zero(page))) {
/*
* Be careful not to clear PageLRU until after we're
@@ -880,6 +879,7 @@ int __isolate_lru_page(struct page *page
*/
ClearPageLRU(page);
ret = 0;
+ mem_cgroup_del_lru(page);
}

return ret;
@@ -1193,7 +1193,6 @@ static unsigned long shrink_inactive_lis
SetPageLRU(page);
lru = page_lru(page);
add_page_to_lru_list(zone, page, lru);
- mem_cgroup_move_lists(page, lru);
if (PageActive(page) && scan_global_lru(sc)) {
int file = !!page_is_file_cache(page);
zone->recent_rotated[file]++;
@@ -1326,7 +1325,7 @@ static void shrink_active_list(unsigned
ClearPageActive(page);

list_move(&page->lru, &zone->lru[lru].list);
- mem_cgroup_move_lists(page, lru);
+ mem_cgroup_add_lru_list(page, lru);
pgmoved++;
if (!pagevec_add(&pvec, page)) {
__mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
@@ -2486,6 +2485,7 @@ retry:

__dec_zone_state(zone, NR_UNEVICTABLE);
list_move(&page->lru, &zone->lru[l].list);
+ mem_cgroup_move_lists(page, LRU_UNEVICTABLE, l);
__inc_zone_state(zone, NR_INACTIVE_ANON + l);
__count_vm_event(UNEVICTABLE_PGRESCUED);
} else {
@@ -2494,6 +2494,7 @@ retry:
*/
SetPageUnevictable(page);
list_move(&page->lru, &zone->lru[LRU_UNEVICTABLE].list);
+ mem_cgroup_rotate_lru_list(page, LRU_UNEVICTABLE);
if (page_evictable(page, NULL))
goto retry;
}
Index: mmotm-2.6.28-Nov10/include/linux/page_cgroup.h
===================================================================
--- mmotm-2.6.28-Nov10.orig/include/linux/page_cgroup.h
+++ mmotm-2.6.28-Nov10/include/linux/page_cgroup.h
@@ -26,10 +26,6 @@ enum {
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) \
@@ -50,19 +46,6 @@ 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);
Index: mmotm-2.6.28-Nov10/mm/swap.c
===================================================================
--- mmotm-2.6.28-Nov10.orig/mm/swap.c
+++ mmotm-2.6.28-Nov10/mm/swap.c
@@ -168,7 +168,6 @@ void activate_page(struct page *page)
lru += LRU_ACTIVE;
add_page_to_lru_list(zone, page, lru);
__count_vm_event(PGACTIVATE);
- mem_cgroup_move_lists(page, lru);

zone->recent_rotated[!!file]++;
zone->recent_scanned[!!file]++;

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