[RFC][PATCH][0/4] Memory controller (RSS Control) (v2)

@@ -0,0 +1,33 @@
+/*
+ * memcontrol.h - Memory Controller for containers
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * A(C) Copyright IBM Corporation, 2006-2007
+ *
+ * Author: Balbir Singh <balbir@in.ibm.com>
+ *
+ */
+
+#ifndef _LINUX_MEMCONTROL_H
+#define _LINUX_MEMCONTROL_H
+
+#ifdef CONFIG_CONTAINER_MEMCONTROL
+#ifndef kB
+#define kB 1024			/* One Kilo Byte */
+#endif
+
+#else /* CONFIG_CONTAINER_MEMCONTROL  */
+
+#endif /* CONFIG_CONTAINER_MEMCONTROL */
+#endif /* _LINUX_MEMCONTROL_H */

@@ -306,6 +306,13 @@ config CONTAINER_NS
           for instance virtual servers and checkpoint/restart
           jobs.
 
+config CONTAINER_MEMCONTROL
+	bool "A simple RSS based memory controller"
+	select CONTAINERS
+	help
+	  Provides a simple Resource Controller for monitoring and
+	  controlling the total Resident Set Size of the tasks in a container
+
 config RELAY
 	bool "Kernel->user space relay support (formerly relayfs)"
 	help

@@ -29,3 +29,4 @@ obj-$(CONFIG_MEMORY_HOTPLUG) += memory_h
 obj-$(CONFIG_FS_XIP) += filemap_xip.o
 obj-$(CONFIG_MIGRATION) += migrate.o
 obj-$(CONFIG_SMP) += allocpercpu.o
+obj-$(CONFIG_CONTAINER_MEMCONTROL) += memcontrol.o

@@ -0,0 +1,193 @@
+/*
+ * memcontrol.c - Memory Controller for containers
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * A(C) Copyright IBM Corporation, 2006-2007
+ *
+ * Author: Balbir Singh <balbir@in.ibm.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/parser.h>
+#include <linux/fs.h>
+#include <linux/container.h>
+#include <linux/memcontrol.h>
+
+#include <asm/uaccess.h>
+
+#define RES_USAGE_NO_LIMIT	0
+static const char version[] = "0.1";
+
+struct res_counter {
+	atomic_long_t usage;	/* The current usage of the resource being */
+				/* counted 				   */
+	atomic_long_t limit;	/* The limit on the resource		   */
+};
+
+/*
+ * Each task belongs to a container, each container has a struct
+ * memcontrol associated with it
+ */
+struct memcontrol {
+	struct container_subsys_state	css;
+	struct res_counter 		counter;
+};
+
+static struct container_subsys memcontrol_subsys;
+
+static inline struct memcontrol *memcontrol_from_cont(struct container *cont)
+{
+	return container_of(container_subsys_state(cont, &memcontrol_subsys),
+				struct memcontrol, css);
+}
+
+static inline struct memcontrol *memcontrol_from_task(struct task_struct *p)
+{
+	return memcontrol_from_cont(task_container(p, &memcontrol_subsys));
+}
+
+static int memcontrol_create(struct container_subsys *ss,
+				struct container *cont)
+{
+	struct memcontrol *mem = kzalloc(sizeof(*mem), GFP_KERNEL);
+	if (!mem)
+		return -ENOMEM;
+
+	cont->subsys[memcontrol_subsys.subsys_id] = &mem->css;
+	atomic_long_set(&mem->counter.usage, 0);
+	atomic_long_set(&mem->counter.limit, 0);
+	return 0;
+}
+
+static void memcontrol_destroy(struct container_subsys *ss,
+				struct container *cont)
+{
+	kfree(memcontrol_from_cont(cont));
+}
+
+static ssize_t memcontrol_limit_write(struct container *cont,
+					struct cftype *cft, struct file *file,
+					const char __user *userbuf,
+					size_t nbytes, loff_t *ppos)
+{
+	char *buffer;
+	int ret = 0;
+	unsigned long limit;
+	struct memcontrol *mem = memcontrol_from_cont(cont);
+
+	BUG_ON(!mem);
+	buffer = kmalloc(nbytes + 1, GFP_KERNEL);
+	if (buffer == NULL)
+		return -ENOMEM;
+
+	buffer[nbytes] = 0;
+	if (copy_from_user(buffer, userbuf, nbytes)) {
+		ret = -EFAULT;
+		goto out_err;
+	}
+
+	container_manage_lock();
+	if (container_is_removed(cont)) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	limit = simple_strtoul(buffer, NULL, 10);
+	/*
+	 * 0 is a valid limit (unlimited resource usage)
+	 */
+	if (!limit && strcmp(buffer, "0"))
+		goto out_unlock;
+
+	atomic_long_set(&mem->counter.limit, limit);
+	ret = nbytes;
+out_unlock:
+	container_manage_unlock();
+out_err:
+	kfree(buffer);
+	return ret;
+}
+
+static ssize_t memcontrol_limit_read(struct container *cont, struct cftype *cft,
+					struct file *file, char __user *userbuf,
+					size_t nbytes, loff_t *ppos)
+{
+	long limit;
+	char buf[64];		/* Move away from stack later */
+	char *s = buf;
+	struct memcontrol *mem = memcontrol_from_cont(cont);
+
+	limit = atomic_long_read(&mem->counter.limit);
+
+	s += sprintf(s, "limit: %ld pages (%ld kB)\n", limit,
+			(limit * PAGE_SIZE) / kB);
+	return simple_read_from_buffer(userbuf, nbytes, ppos, buf, s - buf);
+}
+
+static ssize_t memcontrol_usage_read(struct container *cont, struct cftype *cft,
+					struct file *file, char __user *userbuf,
+					size_t nbytes, loff_t *ppos)
+{
+	long usage;
+	char buf[64];		/* Move away from stack later */
+	char *s = buf;
+	struct memcontrol *mem = memcontrol_from_cont(cont);
+
+	usage = atomic_long_read(&mem->counter.usage);
+
+	s += sprintf(s, "usage: %ld pages (%ld kB)\n", usage,
+			(usage * PAGE_SIZE) / kB);
+	return simple_read_from_buffer(userbuf, nbytes, ppos, buf, s - buf);
+}
+
+static struct cftype memcontrol_usage = {
+	.name = "memcontrol_usage",
+	.read = memcontrol_usage_read,
+};
+
+static struct cftype memcontrol_limit = {
+	.name = "memcontrol_limit",
+	.write = memcontrol_limit_write,
+	.read = memcontrol_limit_read,
+};
+
+static int memcontrol_populate(struct container_subsys *ss,
+				struct container *cont)
+{
+	int rc;
+	if ((rc = container_add_file(cont, &memcontrol_usage)) < 0)
+		return rc;
+	if ((rc = container_add_file(cont, &memcontrol_limit)) < 0)
+		return rc;
+	return 0;
+}
+
+static struct container_subsys memcontrol_subsys = {
+	.name = "memcontrol",
+	.create = memcontrol_create,
+	.destroy = memcontrol_destroy,
+	.populate = memcontrol_populate,
+};
+
+int __init memcontrol_init(void)
+{
+	int id;
+
+	id = container_register_subsys(&memcontrol_subsys);
+	printk("Initializing memcontrol version %s, id %d\n", version, id);
+	return id < 0 ? id : 0;
+}
+
+module_init(memcontrol_init);

@@ -0,0 +1,70 @@
+Introduction
+------------
+
+The memory controller is a controller module written under the containers
+framework. It can be used to limit the resource usage of a group of
+tasks grouped by the container.
+
+Accounting
+----------
+
+The memory controller tracks the RSS usage of the tasks in the container.
+The definition of RSS was debated on lkml in the following thread
+
+	http://lkml.org/lkml/2006/10/10/130
+
+This patch is flexible, it is easy to adapt the patch to any definition
+of RSS. The current accounting is based on the current definition of
+RSS. Each page mapped is charged to the container.
+
+The accounting is done at two levels, each process has RSS accounting in
+the mm_struct and in the container it belongs to. The mm_struct accounting
+is used when a task switches (migrates to a different) container(s). The
+accounting information for the task is subtracted from the source container
+and added to the destination container. If as result of the migration, the
+destination container goes over limit, no action is taken until some task
+in the destination container runs and tries to map a new page in its
+page table.
+
+The current RSS usage can be seen in the memcontrol_usage file. The value
+is in units of pages.
+
+Control
+-------
+
+The memcontrol_limit file allows the user to set a limit on the number of
+pages that can be mapped by the processes in the container. A special
+value of 0 (which is the default limit of any new container), indicates
+that the container can use unlimited amount of RSS.
+
+Reclaim
+-------
+
+When the limit set in the container is hit, the memory controller starts
+reclaiming pages belonging to the container (simulating a local LRU in
+some sense). isolate_lru_pages() has been modified to isolate lru
+pages belonging to a specific container. Parallel reclaims on the same
+container are not allowed, other tasks end up waiting for the any existing
+reclaim to finish.
+
+The reclaim code uses two internal knobs, retries and pushback. pushback
+specifies the percentage of memory to be reclaimed when the container goes
+over limit. The retries knob, controls how many times reclaim is retried
+before the task is killed (because reclaim failed).
+
+Shared pages are treated specially during reclaim. They are not force
+reclaimed, they are only unmapped from containers which are over limit.
+This ensures that other containers do not pay a penalty for a shared
+page being reclaimed when a paritcular container goes over its limit.
+
+NOTE: All limits are hard limits.
+
+Future Plans
+------------
+
+The current controller implements only RSS control. It is planned to add
+the following components
+
+1. Page Cache control
+2. mlock'ed memory control
+3. kernel memory allocation control (memory allocated on behalf of a task)

@@ -37,6 +37,7 @@ enum {
 };
 
 #ifdef CONFIG_CONTAINER_MEMCONTROL
+#include <linux/wait.h>
 
 #ifndef kB
 #define kB 1024			/* One Kilo Byte */

@@ -53,6 +54,9 @@ extern void memcontrol_mm_free(struct mm
 extern void memcontrol_mm_assign_container(struct mm_struct *mm,
 						struct task_struct *p);
 extern int memcontrol_update_rss(struct mm_struct *mm, int count, bool check);
+extern int memcontrol_mm_overlimit(struct mm_struct *mm, void *sc_cont);
+extern wait_queue_head_t memcontrol_reclaim_wq;
+extern bool memcontrol_reclaim_in_progress;
 
 #else /* CONFIG_CONTAINER_MEMCONTROL  */
 

@@ -76,5 +80,13 @@ static inline int memcontrol_update_rss(
 	return 0;
 }
 
+/*
+ * In the absence of memory control, we always free mappings.
+ */
+static inline int memcontrol_mm_overlimit(struct mm_struct *mm, void *sc_cont)
+{
+	return 1;
+}
+
 #endif /* CONFIG_CONTAINER_MEMCONTROL */
 #endif /* _LINUX_MEMCONTROL_H */

@@ -8,6 +8,7 @@
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/spinlock.h>
+#include <linux/container.h>
 
 /*
  * The anon_vma heads a list of private "related" vmas, to scan if

@@ -90,7 +91,17 @@ static inline void page_dup_rmap(struct 
  * Called from mm/vmscan.c to handle paging out
  */
 int page_referenced(struct page *, int is_locked);
-int try_to_unmap(struct page *, int ignore_refs);
+int try_to_unmap(struct page *, int ignore_refs, struct container *container);
+#ifdef CONFIG_CONTAINER_MEMCONTROL
+bool page_in_container(struct page *page, struct zone *zone,
+			struct container *container);
+#else
+static inline bool page_in_container(struct page *page, struct zone *zone,
+					struct container *container)
+{
+	return true;
+}
+#endif /* CONFIG_CONTAINER_MEMCONTROL */
 
 /*
  * Called from mm/filemap_xip.c to unmap empty zero page

@@ -118,7 +129,12 @@ int page_mkclean(struct page *);
 #define anon_vma_link(vma)	do {} while (0)
 
 #define page_referenced(page,l) TestClearPageReferenced(page)
-#define try_to_unmap(page, refs) SWAP_FAIL
+#define try_to_unmap(page, refs, container) SWAP_FAIL
+static inline bool page_in_container(struct page *page, struct zone *zone,
+					struct container *container)
+{
+	return true;
+}
 
 static inline int page_mkclean(struct page *page)
 {

@@ -6,6 +6,7 @@
 #include <linux/mmzone.h>
 #include <linux/list.h>
 #include <linux/sched.h>
+#include <linux/container.h>
 
 #include <asm/atomic.h>
 #include <asm/page.h>

@@ -188,6 +189,8 @@ extern void swap_setup(void);
 /* linux/mm/vmscan.c */
 extern unsigned long try_to_free_pages(struct zone **, gfp_t);
 extern unsigned long shrink_all_memory(unsigned long nr_pages);
+extern unsigned long memcontrol_shrink_mapped_memory(unsigned long nr_pages,
+						struct container *container);
 extern int vm_swappiness;
 extern int remove_mapping(struct address_space *mapping, struct page *page);
 extern long vm_total_pages;

@@ -24,6 +24,7 @@
 #include <linux/fs.h>
 #include <linux/container.h>
 #include <linux/memcontrol.h>
+#include <linux/swap.h>
 
 #include <asm/uaccess.h>
 

@@ -31,6 +32,12 @@
 static const char version[] = "0.1";
 
 /*
+ * Explore exporting these knobs to user space
+ */
+static const int pushback = 20;	 /* What percentage of memory to reclaim */
+static const int nr_retries = 5; /* How many times do we try to reclaim  */
+
+/*
  * Locking notes
  *
  * Each mm_struct belongs to a container, when the thread group leader

@@ -52,6 +59,9 @@ static const char version[] = "0.1";
 struct memcontrol {
 	struct container_subsys_state	css;
 	struct res_counter 		counter;
+	wait_queue_head_t		wq;
+	bool				reclaim_in_progress;
+	spinlock_t			lock;
 };
 
 static struct container_subsys memcontrol_subsys;

@@ -67,6 +77,41 @@ static inline struct memcontrol *memcont
 	return memcontrol_from_cont(task_container(p, &memcontrol_subsys));
 }
 
+/*
+ * checks if the mm's container and scan control passed container match, if
+ * so, is the container over it's limit. Returns 1 to indicate that the
+ * pages from the mm_struct in question should be reclaimed.
+ */
+int memcontrol_mm_overlimit(struct mm_struct *mm, void *sc_cont)
+{
+	struct container *cont;
+	struct memcontrol *mem;
+	long usage, limit;
+	int ret = 1;
+
+	/*
+ 	 * Regular reclaim, let it proceed as usual
+ 	 */
+	if (!sc_cont)
+		goto out;
+
+	ret = 0;
+	read_lock(&mm->container_lock);
+	cont = mm->container;
+	if (cont != sc_cont)
+		goto out_unlock;
+
+	mem = memcontrol_from_cont(cont);
+	usage = atomic_long_read(&mem->counter.usage);
+	limit = atomic_long_read(&mem->counter.limit);
+	if (limit && (usage > limit))
+		ret = 1;
+out_unlock:
+	read_unlock(&mm->container_lock);
+out:
+	return ret;
+}
+
 int memcontrol_mm_init(struct mm_struct *mm)
 {
 	mm->counter = kmalloc(sizeof(struct res_counter), GFP_KERNEL);

@@ -99,6 +144,46 @@ void memcontrol_mm_assign_container(stru
 	memcontrol_mm_assign_container_direct(mm, cont);
 }
 
+static int memcontrol_check_and_reclaim(struct container *cont, long usage,
+					long limit)
+{
+	unsigned long nr_pages = 0;
+	unsigned long nr_reclaimed = 0;
+	int retries = nr_retries;
+	int ret = 0;
+	struct memcontrol *mem;
+
+	mem = memcontrol_from_cont(cont);
+	spin_lock(&mem->lock);
+	while ((retries-- > 0) && limit && (usage > limit)) {
+		if (mem->reclaim_in_progress) {
+			spin_unlock(&mem->lock);
+			wait_event(mem->wq, !mem->reclaim_in_progress);
+			spin_lock(&mem->lock);
+		} else {
+			if (!nr_pages)
+				nr_pages = (pushback * limit) / 100;
+			mem->reclaim_in_progress = true;
+			spin_unlock(&mem->lock);
+			nr_reclaimed +=
+				memcontrol_shrink_mapped_memory(nr_pages, cont);
+			spin_lock(&mem->lock);
+			mem->reclaim_in_progress = false;
+			wake_up_all(&mem->wq);
+		}
+		/*
+ 		 * Resample usage and limit after reclaim
+ 		 */
+		usage = atomic_long_read(&mem->counter.usage);
+		limit = atomic_long_read(&mem->counter.limit);
+	}
+	spin_unlock(&mem->lock);
+
+	if (limit && (usage > limit))
+		ret = -ENOMEM;
+	return ret;
+}
+
 /*
  * Update the rss usage counters for the mm_struct and the container it belongs
  * to. We do not fail rss for pages shared during fork (see copy_one_pte()).

@@ -120,12 +205,15 @@ int memcontrol_update_rss(struct mm_stru
 	usage = atomic_long_read(&mem->counter.usage);
 	limit = atomic_long_read(&mem->counter.limit);
 	usage += count;
-	if (check && limit && (usage > limit))
-		ret = -ENOMEM;	/* Above limit, fail */
-	else {
-		atomic_long_add(count, &mem->counter.usage);
-		atomic_long_add(count, &mm->counter->usage);
-	}
+
+	if (check)
+		if (memcontrol_check_and_reclaim(cont, usage, limit)) {
+			ret = -ENOMEM;
+			goto out_unlock;
+		}
+
+	atomic_long_add(count, &mem->counter.usage);
+	atomic_long_add(count, &mm->counter->usage);
 
 out_unlock:
 	read_unlock(&mm->container_lock);

@@ -142,6 +230,9 @@ static int memcontrol_create(struct cont
 	cont->subsys[memcontrol_subsys.subsys_id] = &mem->css;
 	atomic_long_set(&mem->counter.usage, 0);
 	atomic_long_set(&mem->counter.limit, 0);
+	init_waitqueue_head(&mem->wq);
+	mem->reclaim_in_progress = false;
+	spin_lock_init(&mem->lock);
 	return 0;
 }
 

@@ -157,8 +248,8 @@ static ssize_t memcontrol_limit_write(st
 					size_t nbytes, loff_t *ppos)
 {
 	char *buffer;
-	int ret = 0;
-	unsigned long limit;
+	int ret = nbytes;
+	unsigned long cur_limit, limit, usage;
 	struct memcontrol *mem = memcontrol_from_cont(cont);
 
 	BUG_ON(!mem);

@@ -186,7 +277,14 @@ static ssize_t memcontrol_limit_write(st
 		goto out_unlock;
 
 	atomic_long_set(&mem->counter.limit, limit);
-	ret = nbytes;
+
+	usage = atomic_read(&mem->counter.usage);
+	cur_limit = atomic_read(&mem->counter.limit);
+	if (limit && (usage > limit))
+		if (memcontrol_check_and_reclaim(cont, usage, cur_limit)) {
+			ret = -EAGAIN;	/* Try again, later */
+			goto out_unlock;
+		}
 out_unlock:
 	container_manage_unlock();
 out_err:

@@ -276,6 +374,12 @@ static void memcontrol_attach(struct con
 	if (cont == old_cont)
 		return;
 
+	/*
+ 	 * See if this can be stopped at the upper layer
+ 	 */
+	if (cont == old_cont)
+		return;
+
 	mem = memcontrol_from_cont(cont);
 	old_mem = memcontrol_from_cont(old_cont);
 

@@ -623,7 +623,7 @@ static int unmap_and_move(new_page_t get
 	/*
 	 * Establish migration ptes or remove ptes
 	 */
-	try_to_unmap(page, 1);
+	try_to_unmap(page, 1, NULL);
 	if (!page_mapped(page))
 		rc = move_to_new_page(newpage, page);
 

@@ -792,7 +792,8 @@ static void try_to_unmap_cluster(unsigne
 	pte_unmap_unlock(pte - 1, ptl);
 }
 
-static int try_to_unmap_anon(struct page *page, int migration)
+static int try_to_unmap_anon(struct page *page, int migration,
+				struct container *container)
 {
 	struct anon_vma *anon_vma;
 	struct vm_area_struct *vma;

@@ -803,6 +804,13 @@ static int try_to_unmap_anon(struct page
 		return ret;
 
 	list_for_each_entry(vma, &anon_vma->head, anon_vma_node) {
+		/*
+ 		 * When reclaiming memory on behalf of overlimit containers
+ 		 * shared pages are spared, they are only unmapped from
+ 		 * the vma's (mm's) whose containers are over limit
+ 		 */
+		if (!memcontrol_mm_overlimit(vma->vm_mm, container))
+			continue;
 		ret = try_to_unmap_one(page, vma, migration);
 		if (ret == SWAP_FAIL || !page_mapped(page))
 			break;

@@ -820,7 +828,8 @@ static int try_to_unmap_anon(struct page
  *
  * This function is only called from try_to_unmap for object-based pages.
  */
-static int try_to_unmap_file(struct page *page, int migration)
+static int try_to_unmap_file(struct page *page, int migration,
+				struct container *container)
 {
 	struct address_space *mapping = page->mapping;
 	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);

@@ -834,6 +843,12 @@ static int try_to_unmap_file(struct page
 
 	spin_lock(&mapping->i_mmap_lock);
 	vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+		/*
+ 		 * If we are reclaiming memory due to containers being overlimit
+ 		 * and this mm is not over it's limit, spare the page
+ 		 */
+		if (!memcontrol_mm_overlimit(vma->vm_mm, container))
+			continue;
 		ret = try_to_unmap_one(page, vma, migration);
 		if (ret == SWAP_FAIL || !page_mapped(page))
 			goto out;

@@ -880,6 +895,8 @@ static int try_to_unmap_file(struct page
 						shared.vm_set.list) {
 			if ((vma->vm_flags & VM_LOCKED) && !migration)
 				continue;
+			if (!memcontrol_mm_overlimit(vma->vm_mm, container))
+				continue;
 			cursor = (unsigned long) vma->vm_private_data;
 			while ( cursor < max_nl_cursor &&
 				cursor < vma->vm_end - vma->vm_start) {

@@ -919,19 +936,92 @@ out:
  * SWAP_AGAIN	- we missed a mapping, try again later
  * SWAP_FAIL	- the page is unswappable
  */
-int try_to_unmap(struct page *page, int migration)
+int try_to_unmap(struct page *page, int migration, struct container *container)
 {
 	int ret;
 
 	BUG_ON(!PageLocked(page));
 
 	if (PageAnon(page))
-		ret = try_to_unmap_anon(page, migration);
+		ret = try_to_unmap_anon(page, migration, container);
 	else
-		ret = try_to_unmap_file(page, migration);
+		ret = try_to_unmap_file(page, migration, container);
 
 	if (!page_mapped(page))
 		ret = SWAP_SUCCESS;
 	return ret;
 }
 
+#ifdef CONFIG_CONTAINER_MEMCONTROL
+bool anon_page_in_container(struct page *page, struct container *container)
+{
+	struct anon_vma *anon_vma;
+	struct vm_area_struct *vma;
+	bool ret = false;
+
+	anon_vma = page_lock_anon_vma(page);
+	if (!anon_vma)
+		return ret;
+
+	list_for_each_entry(vma, &anon_vma->head, anon_vma_node)
+		if (memcontrol_mm_overlimit(vma->vm_mm, container)) {
+			ret = true;
+			break;
+		}
+
+	spin_unlock(&anon_vma->lock);
+	return ret;
+}
+
+bool file_page_in_container(struct page *page, struct container *container)
+{
+	bool ret = false;
+	struct vm_area_struct *vma;
+	struct address_space *mapping = page_mapping(page);
+	struct prio_tree_iter iter;
+	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+
+	if (!mapping)
+		return ret;
+
+	spin_lock(&mapping->i_mmap_lock);
+
+	vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff)
+		/*
+ 		 * Check if the page belongs to the container and it is
+ 		 * overlimit
+ 		 */
+		if (memcontrol_mm_overlimit(vma->vm_mm, container)) {
+			ret = true;
+			goto done;
+		}
+
+	if (list_empty(&mapping->i_mmap_nonlinear))
+		goto done;
+
+	list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
+						shared.vm_set.list)
+		if (memcontrol_mm_overlimit(vma->vm_mm, container)) {
+			ret = true;
+			goto done;
+		}
+done:
+	spin_unlock(&mapping->i_mmap_lock);
+	return ret;
+}
+
+bool page_in_container(struct page *page, struct zone *zone,
+			struct container *container)
+{
+	bool ret;
+
+	spin_unlock_irq(&zone->lru_lock);
+	if (PageAnon(page))
+		ret = anon_page_in_container(page, container);
+	else
+		ret = file_page_in_container(page, container);
+
+	spin_lock_irq(&zone->lru_lock);
+	return ret;
+}
+#endif

@@ -42,6 +42,7 @@
 #include <asm/div64.h>
 
 #include <linux/swapops.h>
+#include <linux/memcontrol.h>
 
 #include "internal.h"
 

@@ -66,6 +67,9 @@ struct scan_control {
 	int swappiness;
 
 	int all_unreclaimable;
+
+	struct container *container;	/* Used by containers for reclaiming */
+					/* pages when the limit is exceeded  */
 };
 
 /*

@@ -507,7 +511,7 @@ static unsigned long shrink_page_list(st
 		 * processes. Try to unmap it here.
 		 */
 		if (page_mapped(page) && mapping) {
-			switch (try_to_unmap(page, 0)) {
+			switch (try_to_unmap(page, 0, sc->container)) {
 			case SWAP_FAIL:
 				goto activate_locked;
 			case SWAP_AGAIN:

@@ -621,19 +625,43 @@ keep:
  */
 static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 		struct list_head *src, struct list_head *dst,
-		unsigned long *scanned)
+		unsigned long *scanned, struct zone *zone,
+		struct container *container, unsigned long max_scan)
 {
 	unsigned long nr_taken = 0;
 	struct page *page;
-	unsigned long scan;
+	unsigned long scan, vscan;
+	LIST_HEAD(skipped_pages);
 
-	for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
+	for (scan = 0, vscan = 0; scan < nr_to_scan && (vscan < max_scan) &&
+					!list_empty(src); scan++, vscan++) {
 		struct list_head *target;
 		page = lru_to_page(src);
 		prefetchw_prev_lru_page(page, src, flags);
 
 		VM_BUG_ON(!PageLRU(page));
 
+		/*
+ 		 * For containers, do not scan the page unless it
+ 		 * belongs to the container we are reclaiming for
+ 		 */
+		if (container) {
+			/*
+			 * Move the page to skipped_pages list, since
+			 * we give up the lru_lock in page_in_container()
+			 * it is important to take page off LRU before
+			 * the routine is called.
+			 */
+			list_move(&page->lru, &skipped_pages);
+			if (!page_in_container(page, zone, container)) {
+				scan--;
+				/*
+				 * Page continues to live in skipped pages
+				 * It will be added back later to the LRU
+				 */
+				continue;
+			}
+		}
 		list_del(&page->lru);
 		target = src;
 		if (likely(get_page_unless_zero(page))) {

@@ -646,10 +674,17 @@ static unsigned long isolate_lru_pages(u
 			target = dst;
 			nr_taken++;
 		} /* else it is being freed elsewhere */
-
 		list_add(&page->lru, target);
+
 	}
 
+	/*
+	 * Add back the skipped pages in LRU order to avoid churning
+	 * the LRU
+	 */
+	if (container)
+		list_splice_tail(&skipped_pages, src);
+
 	*scanned = scan;
 	return nr_taken;
 }

@@ -678,7 +713,8 @@ static unsigned long shrink_inactive_lis
 
 		nr_taken = isolate_lru_pages(sc->swap_cluster_max,
 					     &zone->inactive_list,
-					     &page_list, &nr_scan);
+					     &page_list, &nr_scan, zone,
+					     sc->container, zone->nr_inactive);
 		zone->nr_inactive -= nr_taken;
 		zone->pages_scanned += nr_scan;
 		spin_unlock_irq(&zone->lru_lock);

@@ -823,7 +859,8 @@ force_reclaim_mapped:
 	lru_add_drain();
 	spin_lock_irq(&zone->lru_lock);
 	pgmoved = isolate_lru_pages(nr_pages, &zone->active_list,
-				    &l_hold, &pgscanned);
+				    &l_hold, &pgscanned, zone, sc->container,
+				    zone->nr_active);
 	zone->pages_scanned += pgscanned;
 	zone->nr_active -= pgmoved;
 	spin_unlock_irq(&zone->lru_lock);

@@ -1361,7 +1398,7 @@ void wakeup_kswapd(struct zone *zone, in
 	wake_up_interruptible(&pgdat->kswapd_wait);
 }
 
-#ifdef CONFIG_PM
+#if defined(CONFIG_PM) || defined(CONFIG_CONTAINER_MEMCONTROL)
 /*
  * Helper function for shrink_all_memory().  Tries to reclaim 'nr_pages' pages
  * from LRU lists system-wide, for given pass and priority, and returns the

@@ -1370,7 +1407,7 @@ void wakeup_kswapd(struct zone *zone, in
  * For pass > 3 we also try to shrink the LRU lists that contain a few pages
  */
 static unsigned long shrink_all_zones(unsigned long nr_pages, int prio,
-				      int pass, struct scan_control *sc)
+				      int pass, int max_pass, struct scan_control *sc)
 {
 	struct zone *zone;
 	unsigned long nr_to_scan, ret = 0;

@@ -1386,7 +1423,7 @@ static unsigned long shrink_all_zones(un
 		/* For pass = 0 we don't shrink the active list */
 		if (pass > 0) {
 			zone->nr_scan_active += (zone->nr_active >> prio) + 1;
-			if (zone->nr_scan_active >= nr_pages || pass > 3) {
+			if (zone->nr_scan_active >= nr_pages || pass > max_pass) {
 				zone->nr_scan_active = 0;
 				nr_to_scan = min(nr_pages, zone->nr_active);
 				shrink_active_list(nr_to_scan, zone, sc, prio);

@@ -1394,7 +1431,7 @@ static unsigned long shrink_all_zones(un
 		}
 
 		zone->nr_scan_inactive += (zone->nr_inactive >> prio) + 1;
-		if (zone->nr_scan_inactive >= nr_pages || pass > 3) {
+		if (zone->nr_scan_inactive >= nr_pages || pass > max_pass) {
 			zone->nr_scan_inactive = 0;
 			nr_to_scan = min(nr_pages, zone->nr_inactive);
 			ret += shrink_inactive_list(nr_to_scan, zone, sc);

@@ -1405,7 +1442,9 @@ static unsigned long shrink_all_zones(un
 
 	return ret;
 }
+#endif
 
+#ifdef CONFIG_PM
 static unsigned long count_lru_pages(void)
 {
 	struct zone *zone;

@@ -1477,7 +1516,7 @@ unsigned long shrink_all_memory(unsigned
 			unsigned long nr_to_scan = nr_pages - ret;
 
 			sc.nr_scanned = 0;
-			ret += shrink_all_zones(nr_to_scan, prio, pass, &sc);
+			ret += shrink_all_zones(nr_to_scan, prio, pass, 3, &sc);
 			if (ret >= nr_pages)
 				goto out;