[-mm PATCH 0/10] Memory controller introduction (v7)

[-mm PATCH 0/10] Memory controller introduction (v7)

[Balbir Singh]

Hi, Andrew,

Here's version 7 of the memory controller (against 2.6.23-rc2-mm2). I was
told "7" is a lucky number, so I am hopeful this version of the patchset will
get merged ;)

The salient features of the patches are

a. Provides *zero overhead* for non memory controller users
b. Enable control of both RSS (mapped) and Page Cache (unmapped) pages
c. The infrastructure allows easy addition of other types of memory to control
d. Provides a double LRU: global memory pressure causes reclaim from the
   global LRU; a container on hitting a limit, reclaims from the per
   container LRU

The documentation accompanying this patch has more details on the design
and usage.

Changelog since version 6

1. Port to 2.6.23-rc3-mm1
2. Add new documentation

Tested the patches (with config disabled) and kernbench, lmbench on an
x86_64 box.

For more detailed test results, comments on usage and detailed changelog
please see version 6 of the patches

	http://lwn.net/Articles/246140/

series

mem-control-res-counters-infrastructure
mem-control-setup
mem-control-accounting-setup
mem-control-accounting
mem-control-task-migration
mem-control-lru-and-reclaim
mem-control-out-of-memory
mem-control-choose-rss-vs-rss-and-pagecache
mem-control-per-container-page-referenced
mem-control-documentation

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

[-mm PATCH 1/10] Memory controller resource counters (v7)

[Balbir Singh]

From: Pavel Emelianov <xemul@openvz.org>

Introduce generic structures and routines for resource accounting.

Each resource accounting container is supposed to aggregate it,
container_subsystem_state and its resource-specific members within.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

 include/linux/res_counter.h |  102 +++++++++++++++++++++++++++++++++++++
 init/Kconfig                |    7 ++
 kernel/Makefile             |    1 
 kernel/res_counter.c        |  120 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 230 insertions(+)

diff -puN /dev/null include/linux/res_counter.h
--- /dev/null	2007-06-01 20:42:04.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/res_counter.h	2007-08-24 20:46:06.000000000 +0530
@@ -0,0 +1,102 @@
+#ifndef __RES_COUNTER_H__
+#define __RES_COUNTER_H__
+
+/*
+ * Resource Counters
+ * Contain common data types and routines for resource accounting
+ *
+ * Copyright 2007 OpenVZ SWsoft Inc
+ *
+ * Author: Pavel Emelianov <xemul@openvz.org>
+ *
+ */
+
+#include <linux/container.h>
+
+/*
+ * The core object. the container that wishes to account for some
+ * resource may include this counter into its structures and use
+ * the helpers described beyond
+ */
+
+struct res_counter {
+	/*
+	 * the current resource consumption level
+	 */
+	unsigned long usage;
+	/*
+	 * the limit that usage cannot exceed
+	 */
+	unsigned long limit;
+	/*
+	 * the number of unsuccessful attempts to consume the resource
+	 */
+	unsigned long failcnt;
+	/*
+	 * the lock to protect all of the above.
+	 * the routines below consider this to be IRQ-safe
+	 */
+	spinlock_t lock;
+};
+
+/*
+ * Helpers to interact with userspace
+ * res_counter_read/_write - put/get the specified fields from the
+ * res_counter struct to/from the user
+ *
+ * @counter:     the counter in question
+ * @member:  the field to work with (see RES_xxx below)
+ * @buf:     the buffer to opeate on,...
+ * @nbytes:  its size...
+ * @pos:     and the offset.
+ */
+
+ssize_t res_counter_read(struct res_counter *counter, int member,
+		const char __user *buf, size_t nbytes, loff_t *pos);
+ssize_t res_counter_write(struct res_counter *counter, int member,
+		const char __user *buf, size_t nbytes, loff_t *pos);
+
+/*
+ * the field descriptors. one for each member of res_counter
+ */
+
+enum {
+	RES_USAGE,
+	RES_LIMIT,
+	RES_FAILCNT,
+};
+
+/*
+ * helpers for accounting
+ */
+
+void res_counter_init(struct res_counter *counter);
+
+/*
+ * charge - try to consume more resource.
+ *
+ * @counter: the counter
+ * @val: the amount of the resource. each controller defines its own
+ *       units, e.g. numbers, bytes, Kbytes, etc
+ *
+ * returns 0 on success and <0 if the counter->usage will exceed the
+ * counter->limit _locked call expects the counter->lock to be taken
+ */
+
+int res_counter_charge_locked(struct res_counter *counter, unsigned long val);
+int res_counter_charge(struct res_counter *counter, unsigned long val);
+
+/*
+ * uncharge - tell that some portion of the resource is released
+ *
+ * @counter: the counter
+ * @val: the amount of the resource
+ *
+ * these calls check for usage underflow and show a warning on the console
+ * _locked call expects the counter->lock to be taken
+ */
+
+void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val);
+void res_counter_uncharge(struct res_counter *counter, unsigned long val);
+
+#endif
diff -puN init/Kconfig~mem-control-res-counters-infrastructure init/Kconfig
--- linux-2.6.23-rc2-mm2/init/Kconfig~mem-control-res-counters-infrastructure	2007-08-24 20:46:06.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/init/Kconfig	2007-08-24 20:46:06.000000000 +0530
@@ -337,6 +337,13 @@ config CPUSETS
 
 	  Say N if unsure.
 
+config RESOURCE_COUNTERS
+	bool "Resource counters"
+	help
+	  This option enables controller independent resource accounting
+          infrastructure that works with containers
+	depends on CONTAINERS
+
 config SYSFS_DEPRECATED
 	bool "Create deprecated sysfs files"
 	default y
diff -puN kernel/Makefile~mem-control-res-counters-infrastructure kernel/Makefile
--- linux-2.6.23-rc2-mm2/kernel/Makefile~mem-control-res-counters-infrastructure	2007-08-24 20:46:06.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/kernel/Makefile	2007-08-24 20:46:06.000000000 +0530
@@ -59,6 +59,7 @@ obj-$(CONFIG_RELAY) += relay.o
 obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
 obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
+obj-$(CONFIG_RESOURCE_COUNTERS) += res_counter.o
 
 ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
 # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff -puN /dev/null kernel/res_counter.c
--- /dev/null	2007-06-01 20:42:04.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/kernel/res_counter.c	2007-08-24 20:46:06.000000000 +0530
@@ -0,0 +1,120 @@
+/*
+ * resource containers
+ *
+ * Copyright 2007 OpenVZ SWsoft Inc
+ *
+ * Author: Pavel Emelianov <xemul@openvz.org>
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/parser.h>
+#include <linux/fs.h>
+#include <linux/res_counter.h>
+#include <linux/uaccess.h>
+
+void res_counter_init(struct res_counter *counter)
+{
+	spin_lock_init(&counter->lock);
+	counter->limit = (unsigned long)LONG_MAX;
+}
+
+int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
+{
+	if (counter->usage > (counter->limit - val)) {
+		counter->failcnt++;
+		return -ENOMEM;
+	}
+
+	counter->usage += val;
+	return 0;
+}
+
+int res_counter_charge(struct res_counter *counter, unsigned long val)
+{
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&counter->lock, flags);
+	ret = res_counter_charge_locked(counter, val);
+	spin_unlock_irqrestore(&counter->lock, flags);
+	return ret;
+}
+
+void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)
+{
+	if (WARN_ON(counter->usage < val))
+		val = counter->usage;
+
+	counter->usage -= val;
+}
+
+void res_counter_uncharge(struct res_counter *counter, unsigned long val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&counter->lock, flags);
+	res_counter_uncharge_locked(counter, val);
+	spin_unlock_irqrestore(&counter->lock, flags);
+}
+
+
+static inline unsigned long *res_counter_member(struct res_counter *counter,
+						int member)
+{
+	switch (member) {
+	case RES_USAGE:
+		return &counter->usage;
+	case RES_LIMIT:
+		return &counter->limit;
+	case RES_FAILCNT:
+		return &counter->failcnt;
+	};
+
+	BUG();
+	return NULL;
+}
+
+ssize_t res_counter_read(struct res_counter *counter, int member,
+		const char __user *userbuf, size_t nbytes, loff_t *pos)
+{
+	unsigned long *val;
+	char buf[64], *s;
+
+	s = buf;
+	val = res_counter_member(counter, member);
+	s += sprintf(s, "%lu\n", *val);
+	return simple_read_from_buffer((void __user *)userbuf, nbytes,
+			pos, buf, s - buf);
+}
+
+ssize_t res_counter_write(struct res_counter *counter, int member,
+		const char __user *userbuf, size_t nbytes, loff_t *pos)
+{
+	int ret;
+	char *buf, *end;
+	unsigned long tmp, *val;
+
+	buf = kmalloc(nbytes + 1, GFP_KERNEL);
+	ret = -ENOMEM;
+	if (buf == NULL)
+		goto out;
+
+	buf[nbytes] = '\0';
+	ret = -EFAULT;
+	if (copy_from_user(buf, userbuf, nbytes))
+		goto out_free;
+
+	ret = -EINVAL;
+	tmp = simple_strtoul(buf, &end, 10);
+	if (*end != '\0')
+		goto out_free;
+
+	val = res_counter_member(counter, member);
+	*val = tmp;
+	ret = nbytes;
+out_free:
+	kfree(buf);
+out:
+	return ret;
+}
_

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

[-mm PATCH 2/10] Memory controller containers setup (v7)

[Balbir Singh]

Changelong
1. use depends instead of select in init/Kconfig
2. Port to v11
3. Clean up the usage of names (container files) for v11

Setup the memory container and add basic hooks and controls to integrate
and work with the container.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

 include/linux/container_subsys.h |    6 +
 include/linux/memcontrol.h       |   21 ++++++
 init/Kconfig                     |    7 ++
 mm/Makefile                      |    1 
 mm/memcontrol.c                  |  127 +++++++++++++++++++++++++++++++++++++++
 5 files changed, 162 insertions(+)

diff -puN include/linux/container_subsys.h~mem-control-setup include/linux/container_subsys.h
--- linux-2.6.23-rc2-mm2/include/linux/container_subsys.h~mem-control-setup	2007-08-24 20:46:06.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/container_subsys.h	2007-08-24 20:46:06.000000000 +0530
@@ -30,3 +30,9 @@ SUBSYS(ns)
 #endif
 
 /* */
+
+#ifdef CONFIG_CONTAINER_MEM_CONT
+SUBSYS(mem_container)
+#endif
+
+/* */
diff -puN /dev/null include/linux/memcontrol.h
--- /dev/null	2007-06-01 20:42:04.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/memcontrol.h	2007-08-24 20:46:06.000000000 +0530
@@ -0,0 +1,21 @@
+/* memcontrol.h - Memory Controller
+ *
+ * Copyright IBM Corporation, 2007
+ * Author Balbir Singh <balbir@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _LINUX_MEMCONTROL_H
+#define _LINUX_MEMCONTROL_H
+
+#endif /* _LINUX_MEMCONTROL_H */
+
diff -puN init/Kconfig~mem-control-setup init/Kconfig
--- linux-2.6.23-rc2-mm2/init/Kconfig~mem-control-setup	2007-08-24 20:46:06.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/init/Kconfig	2007-08-24 20:46:06.000000000 +0530
@@ -364,6 +364,13 @@ config SYSFS_DEPRECATED
 	  If you are using a distro that was released in 2006 or later,
 	  it should be safe to say N here.
 
+config CONTAINER_MEM_CONT
+	bool "Memory controller for containers"
+	depends on CONTAINERS && RESOURCE_COUNTERS
+	help
+	  Provides a memory controller that manages both page cache and
+	  RSS memory.
+
 config PROC_PID_CPUSET
 	bool "Include legacy /proc/<pid>/cpuset file"
 	depends on CPUSETS
diff -puN mm/Makefile~mem-control-setup mm/Makefile
--- linux-2.6.23-rc2-mm2/mm/Makefile~mem-control-setup	2007-08-24 20:46:06.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/Makefile	2007-08-24 20:46:06.000000000 +0530
@@ -31,4 +31,5 @@ obj-$(CONFIG_FS_XIP) += filemap_xip.o
 obj-$(CONFIG_MIGRATION) += migrate.o
 obj-$(CONFIG_SMP) += allocpercpu.o
 obj-$(CONFIG_QUICKLIST) += quicklist.o
+obj-$(CONFIG_CONTAINER_MEM_CONT) += memcontrol.o
 
diff -puN /dev/null mm/memcontrol.c
--- /dev/null	2007-06-01 20:42:04.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/memcontrol.c	2007-08-24 20:46:06.000000000 +0530
@@ -0,0 +1,127 @@
+/* memcontrol.c - Memory Controller
+ *
+ * Copyright IBM Corporation, 2007
+ * Author Balbir Singh <balbir@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/res_counter.h>
+#include <linux/memcontrol.h>
+#include <linux/container.h>
+
+struct container_subsys mem_container_subsys;
+
+/*
+ * The memory controller data structure. The memory controller controls both
+ * page cache and RSS per container. We would eventually like to provide
+ * statistics based on the statistics developed by Rik Van Riel for clock-pro,
+ * to help the administrator determine what knobs to tune.
+ *
+ * TODO: Add a water mark for the memory controller. Reclaim will begin when
+ * we hit the water mark.
+ */
+struct mem_container {
+	struct container_subsys_state css;
+	/*
+	 * the counter to account for memory usage
+	 */
+	struct res_counter res;
+};
+
+/*
+ * A page_container page is associated with every page descriptor. The
+ * page_container helps us identify information about the container
+ */
+struct page_container {
+	struct list_head lru;		/* per container LRU list */
+	struct page *page;
+	struct mem_container *mem_container;
+};
+
+
+static inline
+struct mem_container *mem_container_from_cont(struct container *cont)
+{
+	return container_of(container_subsys_state(cont,
+				mem_container_subsys_id), struct mem_container,
+				css);
+}
+
+static ssize_t mem_container_read(struct container *cont, struct cftype *cft,
+			struct file *file, char __user *userbuf, size_t nbytes,
+			loff_t *ppos)
+{
+	return res_counter_read(&mem_container_from_cont(cont)->res,
+				cft->private, userbuf, nbytes, ppos);
+}
+
+static ssize_t mem_container_write(struct container *cont, struct cftype *cft,
+				struct file *file, const char __user *userbuf,
+				size_t nbytes, loff_t *ppos)
+{
+	return res_counter_write(&mem_container_from_cont(cont)->res,
+				cft->private, userbuf, nbytes, ppos);
+}
+
+static struct cftype mem_container_files[] = {
+	{
+		.name = "usage",
+		.private = RES_USAGE,
+		.read = mem_container_read,
+	},
+	{
+		.name = "limit",
+		.private = RES_LIMIT,
+		.write = mem_container_write,
+		.read = mem_container_read,
+	},
+	{
+		.name = "failcnt",
+		.private = RES_FAILCNT,
+		.read = mem_container_read,
+	},
+};
+
+static struct container_subsys_state *
+mem_container_create(struct container_subsys *ss, struct container *cont)
+{
+	struct mem_container *mem;
+
+	mem = kzalloc(sizeof(struct mem_container), GFP_KERNEL);
+	if (!mem)
+		return -ENOMEM;
+
+	res_counter_init(&mem->res);
+	return &mem->css;
+}
+
+static void mem_container_destroy(struct container_subsys *ss,
+				struct container *cont)
+{
+	kfree(mem_container_from_cont(cont));
+}
+
+static int mem_container_populate(struct container_subsys *ss,
+				struct container *cont)
+{
+	return container_add_files(cont, ss, mem_container_files,
+					ARRAY_SIZE(mem_container_files));
+}
+
+struct container_subsys mem_container_subsys = {
+	.name = "memory",
+	.subsys_id = mem_container_subsys_id,
+	.create = mem_container_create,
+	.destroy = mem_container_destroy,
+	.populate = mem_container_populate,
+	.early_init = 0,
+};
_

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

[-mm PATCH 3/10] Memory controller accounting setup (v7)

[Balbir Singh]

From: Pavel Emelianov <xemul@openvz.org>

Changelog for v5

1. Remove inclusion of memcontrol.h from mm_types.h

Changelog

As per Paul's review comments

1. Drop css_get() for the root memory container
2. Use mem_container_from_task() as an optimization instead of using
   mem_container_from_cont() along with task_container.

Basic setup routines, the mm_struct has a pointer to the container that
it belongs to and the the page has a page_container associated with it.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

 include/linux/memcontrol.h |   36 ++++++++++++++++++++++++++++
 include/linux/mm_types.h   |    6 ++++
 include/linux/sched.h      |    1 
 kernel/fork.c              |   11 ++++++--
 mm/memcontrol.c            |   57 +++++++++++++++++++++++++++++++++++++++++----
 5 files changed, 104 insertions(+), 7 deletions(-)

diff -puN include/linux/memcontrol.h~mem-control-accounting-setup include/linux/memcontrol.h
--- linux-2.6.23-rc2-mm2/include/linux/memcontrol.h~mem-control-accounting-setup	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/memcontrol.h	2007-08-24 20:46:07.000000000 +0530
@@ -3,6 +3,9 @@
  * Copyright IBM Corporation, 2007
  * Author Balbir Singh <balbir@linux.vnet.ibm.com>
  *
+ * Copyright 2007 OpenVZ SWsoft Inc
+ * Author: Pavel Emelianov <xemul@openvz.org>
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -17,5 +20,38 @@
 #ifndef _LINUX_MEMCONTROL_H
 #define _LINUX_MEMCONTROL_H
 
+struct mem_container;
+struct page_container;
+
+#ifdef CONFIG_CONTAINER_MEM_CONT
+
+extern void mm_init_container(struct mm_struct *mm, struct task_struct *p);
+extern void mm_free_container(struct mm_struct *mm);
+extern void page_assign_page_container(struct page *page,
+					struct page_container *pc);
+extern struct page_container *page_get_page_container(struct page *page);
+
+#else /* CONFIG_CONTAINER_MEM_CONT */
+static inline void mm_init_container(struct mm_struct *mm,
+					struct task_struct *p)
+{
+}
+
+static inline void mm_free_container(struct mm_struct *mm)
+{
+}
+
+static inline void page_assign_page_container(struct page *page,
+						struct page_container *pc)
+{
+}
+
+static inline struct page_container *page_get_page_container(struct page *page)
+{
+	return NULL;
+}
+
+#endif /* CONFIG_CONTAINER_MEM_CONT */
+
 #endif /* _LINUX_MEMCONTROL_H */
 
diff -puN include/linux/mm_types.h~mem-control-accounting-setup include/linux/mm_types.h
--- linux-2.6.23-rc2-mm2/include/linux/mm_types.h~mem-control-accounting-setup	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/mm_types.h	2007-08-24 20:46:07.000000000 +0530
@@ -96,6 +96,9 @@ struct page {
 	unsigned int gfp_mask;
 	unsigned long trace[8];
 #endif
+#ifdef CONFIG_CONTAINER_MEM_CONT
+	unsigned long page_container;
+#endif
 };
 
 /*
@@ -227,6 +230,9 @@ struct mm_struct {
 	/* aio bits */
 	rwlock_t		ioctx_list_lock;
 	struct kioctx		*ioctx_list;
+#ifdef CONFIG_CONTAINER_MEM_CONT
+	struct mem_container *mem_container;
+#endif
 };
 
 #endif /* _LINUX_MM_TYPES_H */
diff -puN include/linux/sched.h~mem-control-accounting-setup include/linux/sched.h
--- linux-2.6.23-rc2-mm2/include/linux/sched.h~mem-control-accounting-setup	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/sched.h	2007-08-24 20:46:07.000000000 +0530
@@ -88,6 +88,7 @@ struct sched_param {
 
 #include <asm/processor.h>
 
+struct mem_container;
 struct exec_domain;
 struct futex_pi_state;
 struct bio;
diff -puN kernel/fork.c~mem-control-accounting-setup kernel/fork.c
--- linux-2.6.23-rc2-mm2/kernel/fork.c~mem-control-accounting-setup	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/kernel/fork.c	2007-08-24 20:46:07.000000000 +0530
@@ -51,6 +51,7 @@
 #include <linux/random.h>
 #include <linux/tty.h>
 #include <linux/proc_fs.h>
+#include <linux/memcontrol.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -329,7 +330,7 @@ __cacheline_aligned_in_smp DEFINE_SPINLO
 
 #include <linux/init_task.h>
 
-static struct mm_struct * mm_init(struct mm_struct * mm)
+static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
 {
 	atomic_set(&mm->mm_users, 1);
 	atomic_set(&mm->mm_count, 1);
@@ -346,11 +347,14 @@ static struct mm_struct * mm_init(struct
 	mm->ioctx_list = NULL;
 	mm->free_area_cache = TASK_UNMAPPED_BASE;
 	mm->cached_hole_size = ~0UL;
+	mm_init_container(mm, p);
 
 	if (likely(!mm_alloc_pgd(mm))) {
 		mm->def_flags = 0;
 		return mm;
 	}
+
+	mm_free_container(mm);
 	free_mm(mm);
 	return NULL;
 }
@@ -365,7 +369,7 @@ struct mm_struct * mm_alloc(void)
 	mm = allocate_mm();
 	if (mm) {
 		memset(mm, 0, sizeof(*mm));
-		mm = mm_init(mm);
+		mm = mm_init(mm, current);
 	}
 	return mm;
 }
@@ -379,6 +383,7 @@ void fastcall __mmdrop(struct mm_struct 
 {
 	BUG_ON(mm == &init_mm);
 	mm_free_pgd(mm);
+	mm_free_container(mm);
 	destroy_context(mm);
 	free_mm(mm);
 }
@@ -499,7 +504,7 @@ static struct mm_struct *dup_mm(struct t
 	mm->token_priority = 0;
 	mm->last_interval = 0;
 
-	if (!mm_init(mm))
+	if (!mm_init(mm, tsk))
 		goto fail_nomem;
 
 	if (init_new_context(tsk, mm))
diff -puN mm/memcontrol.c~mem-control-accounting-setup mm/memcontrol.c
--- linux-2.6.23-rc2-mm2/mm/memcontrol.c~mem-control-accounting-setup	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/memcontrol.c	2007-08-24 20:46:07.000000000 +0530
@@ -3,6 +3,9 @@
  * Copyright IBM Corporation, 2007
  * Author Balbir Singh <balbir@linux.vnet.ibm.com>
  *
+ * Copyright 2007 OpenVZ SWsoft Inc
+ * Author: Pavel Emelianov <xemul@openvz.org>
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -17,6 +20,7 @@
 #include <linux/res_counter.h>
 #include <linux/memcontrol.h>
 #include <linux/container.h>
+#include <linux/mm.h>
 
 struct container_subsys mem_container_subsys;
 
@@ -35,6 +39,13 @@ struct mem_container {
 	 * the counter to account for memory usage
 	 */
 	struct res_counter res;
+	/*
+	 * Per container active and inactive list, similar to the
+	 * per zone LRU lists.
+	 * TODO: Consider making these lists per zone
+	 */
+	struct list_head active_list;
+	struct list_head inactive_list;
 };
 
 /*
@@ -56,6 +67,37 @@ struct mem_container *mem_container_from
 				css);
 }
 
+static inline
+struct mem_container *mem_container_from_task(struct task_struct *p)
+{
+	return container_of(task_subsys_state(p, mem_container_subsys_id),
+				struct mem_container, css);
+}
+
+void mm_init_container(struct mm_struct *mm, struct task_struct *p)
+{
+	struct mem_container *mem;
+
+	mem = mem_container_from_task(p);
+	css_get(&mem->css);
+	mm->mem_container = mem;
+}
+
+void mm_free_container(struct mm_struct *mm)
+{
+	css_put(&mm->mem_container->css);
+}
+
+void page_assign_page_container(struct page *page, struct page_container *pc)
+{
+	page->page_container = (unsigned long)pc;
+}
+
+struct page_container *page_get_page_container(struct page *page)
+{
+	return page->page_container;
+}
+
 static ssize_t mem_container_read(struct container *cont, struct cftype *cft,
 			struct file *file, char __user *userbuf, size_t nbytes,
 			loff_t *ppos)
@@ -91,14 +133,21 @@ static struct cftype mem_container_files
 	},
 };
 
+static struct mem_container init_mem_container;
+
 static struct container_subsys_state *
 mem_container_create(struct container_subsys *ss, struct container *cont)
 {
 	struct mem_container *mem;
 
-	mem = kzalloc(sizeof(struct mem_container), GFP_KERNEL);
-	if (!mem)
-		return -ENOMEM;
+	if (unlikely((cont->parent) == NULL)) {
+		mem = &init_mem_container;
+		init_mm.mem_container = mem;
+	} else
+		mem = kzalloc(sizeof(struct mem_container), GFP_KERNEL);
+
+	if (mem == NULL)
+		return NULL;
 
 	res_counter_init(&mem->res);
 	return &mem->css;
@@ -123,5 +172,5 @@ struct container_subsys mem_container_su
 	.create = mem_container_create,
 	.destroy = mem_container_destroy,
 	.populate = mem_container_populate,
-	.early_init = 0,
+	.early_init = 1,
 };
_

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

[-mm PATCH 4/10] Memory controller memory accounting (v7)

[Balbir Singh]

Changelog for v6
1. Do a css_put() in the case of a race in allocating page containers
   (YAMAMOTO Takashi)

Changelog for v5
1. Rename meta_page to page_container
2. Remove PG_metapage and use the lower bit of the page_container pointer
   for locking

Changelog for v3

1. Fix a probable leak with meta_page's (pointed out by Paul Menage)
2. Introduce a wrapper around mem_container_uncharge for uncharging pages
   mem_container_uncharge_page()

Changelog

1. Improved error handling, uncharge on errors and check to see if we are
   leaking pages (review by YAMAMOTO Takashi)

Add the accounting hooks. The accounting is carried out for RSS and Page
Cache (unmapped) pages. There is now a common limit and accounting for both.
The RSS accounting is accounted at page_add_*_rmap() and page_remove_rmap()
time. Page cache is accounted at add_to_page_cache(),
__delete_from_page_cache(). Swap cache is also accounted for.

Each page's page_container is protected with the last bit of the page_container
pointer, this makes handling of race conditions involving simultaneous
mappings of a page easier. A reference count is kept in the page_container to
deal with cases where a page might be unmapped from the RSS of all tasks, but
still lives in the page cache.

Credits go to Vaidyanathan Srinivasan for helping with reference counting work
of the page container. Almost all of the page cache accounting code has help
from Vaidyanathan Srinivasan.

Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

 include/linux/memcontrol.h |   20 +++++
 mm/filemap.c               |   12 ++-
 mm/memcontrol.c            |  166 ++++++++++++++++++++++++++++++++++++++++++++-
 mm/memory.c                |   43 ++++++++++-
 mm/migrate.c               |    6 +
 mm/page_alloc.c            |    3 
 mm/rmap.c                  |   17 ++++
 mm/swap_state.c            |   12 ++-
 mm/swapfile.c              |   41 ++++++-----
 9 files changed, 293 insertions(+), 27 deletions(-)

diff -puN include/linux/memcontrol.h~mem-control-accounting include/linux/memcontrol.h
--- linux-2.6.23-rc2-mm2/include/linux/memcontrol.h~mem-control-accounting	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/memcontrol.h	2007-08-24 20:46:07.000000000 +0530
@@ -30,6 +30,13 @@ extern void mm_free_container(struct mm_
 extern void page_assign_page_container(struct page *page,
 					struct page_container *pc);
 extern struct page_container *page_get_page_container(struct page *page);
+extern int mem_container_charge(struct page *page, struct mm_struct *mm);
+extern void mem_container_uncharge(struct page_container *pc);
+
+static inline void mem_container_uncharge_page(struct page *page)
+{
+	mem_container_uncharge(page_get_page_container(page));
+}
 
 #else /* CONFIG_CONTAINER_MEM_CONT */
 static inline void mm_init_container(struct mm_struct *mm,
@@ -51,6 +58,19 @@ static inline struct page_container *pag
 	return NULL;
 }
 
+static inline int mem_container_charge(struct page *page, struct mm_struct *mm)
+{
+	return 0;
+}
+
+static inline void mem_container_uncharge(struct page_container *pc)
+{
+}
+
+static inline void mem_container_uncharge_page(struct page *page)
+{
+}
+
 #endif /* CONFIG_CONTAINER_MEM_CONT */
 
 #endif /* _LINUX_MEMCONTROL_H */
diff -puN include/linux/page-flags.h~mem-control-accounting include/linux/page-flags.h
diff -puN mm/filemap.c~mem-control-accounting mm/filemap.c
--- linux-2.6.23-rc2-mm2/mm/filemap.c~mem-control-accounting	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/filemap.c	2007-08-24 20:46:07.000000000 +0530
@@ -31,6 +31,7 @@
 #include <linux/syscalls.h>
 #include <linux/cpuset.h>
 #include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */
+#include <linux/memcontrol.h>
 #include "internal.h"
 
 /*
@@ -116,6 +117,7 @@ void __remove_from_page_cache(struct pag
 {
 	struct address_space *mapping = page->mapping;
 
+	mem_container_uncharge_page(page);
 	radix_tree_delete(&mapping->page_tree, page->index);
 	page->mapping = NULL;
 	mapping->nrpages--;
@@ -442,6 +444,11 @@ int add_to_page_cache(struct page *page,
 	int error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
 
 	if (error == 0) {
+
+		error = mem_container_charge(page, current->mm);
+		if (error)
+			goto out;
+
 		write_lock_irq(&mapping->tree_lock);
 		error = radix_tree_insert(&mapping->page_tree, offset, page);
 		if (!error) {
@@ -451,10 +458,13 @@ int add_to_page_cache(struct page *page,
 			page->index = offset;
 			mapping->nrpages++;
 			__inc_zone_page_state(page, NR_FILE_PAGES);
-		}
+		} else
+			mem_container_uncharge_page(page);
+
 		write_unlock_irq(&mapping->tree_lock);
 		radix_tree_preload_end();
 	}
+out:
 	return error;
 }
 EXPORT_SYMBOL(add_to_page_cache);
diff -puN mm/memcontrol.c~mem-control-accounting mm/memcontrol.c
--- linux-2.6.23-rc2-mm2/mm/memcontrol.c~mem-control-accounting	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/memcontrol.c	2007-08-24 20:46:07.000000000 +0530
@@ -21,6 +21,9 @@
 #include <linux/memcontrol.h>
 #include <linux/container.h>
 #include <linux/mm.h>
+#include <linux/page-flags.h>
+#include <linux/bit_spinlock.h>
+#include <linux/rcupdate.h>
 
 struct container_subsys mem_container_subsys;
 
@@ -31,7 +34,9 @@ struct container_subsys mem_container_su
  * to help the administrator determine what knobs to tune.
  *
  * TODO: Add a water mark for the memory controller. Reclaim will begin when
- * we hit the water mark.
+ * we hit the water mark. May be even add a low water mark, such that
+ * no reclaim occurs from a container at it's low water mark, this is
+ * a feature that will be implemented much later in the future.
  */
 struct mem_container {
 	struct container_subsys_state css;
@@ -49,6 +54,14 @@ struct mem_container {
 };
 
 /*
+ * We use the lower bit of the page->page_container pointer as a bit spin
+ * lock. We need to ensure that page->page_container is atleast two
+ * byte aligned (based on comments from Nick Piggin)
+ */
+#define PAGE_CONTAINER_LOCK_BIT 	0x0
+#define PAGE_CONTAINER_LOCK 		(1 << PAGE_CONTAINER_LOCK_BIT)
+
+/*
  * A page_container page is associated with every page descriptor. The
  * page_container helps us identify information about the container
  */
@@ -56,6 +69,8 @@ struct page_container {
 	struct list_head lru;		/* per container LRU list */
 	struct page *page;
 	struct mem_container *mem_container;
+	atomic_t ref_cnt;		/* Helpful when pages move b/w  */
+					/* mapped and cached states     */
 };
 
 
@@ -88,14 +103,157 @@ void mm_free_container(struct mm_struct 
 	css_put(&mm->mem_container->css);
 }
 
+static inline int page_container_locked(struct page *page)
+{
+	return bit_spin_is_locked(PAGE_CONTAINER_LOCK_BIT,
+					&page->page_container);
+}
+
 void page_assign_page_container(struct page *page, struct page_container *pc)
 {
-	page->page_container = (unsigned long)pc;
+	int locked;
+
+	/*
+	 * While resetting the page_container we might not hold the
+	 * page_container lock. free_hot_cold_page() is an example
+	 * of such a scenario
+	 */
+	if (pc)
+		VM_BUG_ON(!page_container_locked(page));
+	locked = (page->page_container & PAGE_CONTAINER_LOCK);
+	page->page_container = ((unsigned long)pc | locked);
 }
 
 struct page_container *page_get_page_container(struct page *page)
 {
-	return page->page_container;
+	return (struct page_container *)
+		(page->page_container & ~PAGE_CONTAINER_LOCK);
+}
+
+void __always_inline lock_page_container(struct page *page)
+{
+	bit_spin_lock(PAGE_CONTAINER_LOCK_BIT, &page->page_container);
+	VM_BUG_ON(!page_container_locked(page));
+}
+
+void __always_inline unlock_page_container(struct page *page)
+{
+	bit_spin_unlock(PAGE_CONTAINER_LOCK_BIT, &page->page_container);
+}
+
+/*
+ * Charge the memory controller for page usage.
+ * Return
+ * 0 if the charge was successful
+ * < 0 if the container is over its limit
+ */
+int mem_container_charge(struct page *page, struct mm_struct *mm)
+{
+	struct mem_container *mem;
+	struct page_container *pc, *race_pc;
+
+	/*
+	 * Should page_container's go to their own slab?
+	 * One could optimize the performance of the charging routine
+	 * by saving a bit in the page_flags and using it as a lock
+	 * to see if the container page already has a page_container associated
+	 * with it
+	 */
+	lock_page_container(page);
+	pc = page_get_page_container(page);
+	/*
+	 * The page_container exists and the page has already been accounted
+	 */
+	if (pc) {
+		atomic_inc(&pc->ref_cnt);
+		goto done;
+	}
+
+	unlock_page_container(page);
+
+	pc = kzalloc(sizeof(struct page_container), GFP_KERNEL);
+	if (pc == NULL)
+		goto err;
+
+	rcu_read_lock();
+	/*
+	 * We always charge the container the mm_struct belongs to
+	 * the mm_struct's mem_container 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 (!mm)
+		mm = &init_mm;
+
+	mem = rcu_dereference(mm->mem_container);
+	/*
+	 * For every charge from the container, increment reference
+	 * count
+	 */
+	css_get(&mem->css);
+	rcu_read_unlock();
+
+	/*
+	 * If we created the page_container, we should free it on exceeding
+	 * the container limit.
+	 */
+	if (res_counter_charge(&mem->res, 1)) {
+		css_put(&mem->css);
+		goto free_pc;
+	}
+
+	lock_page_container(page);
+	/*
+	 * Check if somebody else beat us to allocating the page_container
+	 */
+	race_pc = page_get_page_container(page);
+	if (race_pc) {
+		kfree(pc);
+		pc = race_pc;
+		atomic_inc(&pc->ref_cnt);
+		res_counter_uncharge(&mem->res, 1);
+		css_put(&mem->css);
+		goto done;
+	}
+
+	atomic_set(&pc->ref_cnt, 1);
+	pc->mem_container = mem;
+	pc->page = page;
+	page_assign_page_container(page, pc);
+
+done:
+	unlock_page_container(page);
+	return 0;
+free_pc:
+	kfree(pc);
+	return -ENOMEM;
+err:
+	unlock_page_container(page);
+	return -ENOMEM;
+}
+
+/*
+ * Uncharging is always a welcome operation, we never complain, simply
+ * uncharge.
+ */
+void mem_container_uncharge(struct page_container *pc)
+{
+	struct mem_container *mem;
+	struct page *page;
+
+	if (!pc)
+		return;
+
+	if (atomic_dec_and_test(&pc->ref_cnt)) {
+		page = pc->page;
+		lock_page_container(page);
+		mem = pc->mem_container;
+		css_put(&mem->css);
+		page_assign_page_container(page, NULL);
+		unlock_page_container(page);
+		res_counter_uncharge(&mem->res, 1);
+		kfree(pc);
+	}
 }
 
 static ssize_t mem_container_read(struct container *cont, struct cftype *cft,
@@ -150,6 +308,8 @@ mem_container_create(struct container_su
 		return NULL;
 
 	res_counter_init(&mem->res);
+	INIT_LIST_HEAD(&mem->active_list);
+	INIT_LIST_HEAD(&mem->inactive_list);
 	return &mem->css;
 }
 
diff -puN mm/memory.c~mem-control-accounting mm/memory.c
--- linux-2.6.23-rc2-mm2/mm/memory.c~mem-control-accounting	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/memory.c	2007-08-24 20:46:07.000000000 +0530
@@ -50,6 +50,7 @@
 #include <linux/delayacct.h>
 #include <linux/init.h>
 #include <linux/writeback.h>
+#include <linux/memcontrol.h>
 
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
@@ -1136,14 +1137,18 @@ static int insert_page(struct mm_struct 
 	pte_t *pte;
 	spinlock_t *ptl;  
 
+	retval = mem_container_charge(page, mm);
+	if (retval)
+		goto out;
+
 	retval = -EINVAL;
 	if (PageAnon(page))
-		goto out;
+		goto out_uncharge;
 	retval = -ENOMEM;
 	flush_dcache_page(page);
 	pte = get_locked_pte(mm, addr, &ptl);
 	if (!pte)
-		goto out;
+		goto out_uncharge;
 	retval = -EBUSY;
 	if (!pte_none(*pte))
 		goto out_unlock;
@@ -1155,8 +1160,11 @@ static int insert_page(struct mm_struct 
 	set_pte_at(mm, addr, pte, mk_pte(page, prot));
 
 	retval = 0;
+	return retval;
 out_unlock:
 	pte_unmap_unlock(pte, ptl);
+out_uncharge:
+	mem_container_uncharge_page(page);
 out:
 	return retval;
 }
@@ -1629,6 +1637,9 @@ gotten:
 		goto oom;
 	cow_user_page(new_page, old_page, address, vma);
 
+	if (mem_container_charge(new_page, mm))
+		goto oom_free_new;
+
 	/*
 	 * Re-check the pte - we dropped the lock
 	 */
@@ -1660,7 +1671,9 @@ gotten:
 		/* Free the old page.. */
 		new_page = old_page;
 		ret |= VM_FAULT_WRITE;
-	}
+	} else
+		mem_container_uncharge_page(new_page);
+
 	if (new_page)
 		page_cache_release(new_page);
 	if (old_page)
@@ -1681,6 +1694,8 @@ unlock:
 		put_page(dirty_page);
 	}
 	return ret;
+oom_free_new:
+	__free_page(new_page);
 oom:
 	if (old_page)
 		page_cache_release(old_page);
@@ -2085,6 +2100,11 @@ static int do_swap_page(struct mm_struct
 	}
 
 	delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+	if (mem_container_charge(page, mm)) {
+		ret = VM_FAULT_OOM;
+		goto out;
+	}
+
 	mark_page_accessed(page);
 	lock_page(page);
 
@@ -2121,8 +2141,10 @@ static int do_swap_page(struct mm_struct
 	if (write_access) {
 		/* XXX: We could OR the do_wp_page code with this one? */
 		if (do_wp_page(mm, vma, address,
-				page_table, pmd, ptl, pte) & VM_FAULT_OOM)
+				page_table, pmd, ptl, pte) & VM_FAULT_OOM) {
+			mem_container_uncharge_page(page);
 			ret = VM_FAULT_OOM;
+		}
 		goto out;
 	}
 
@@ -2133,6 +2155,7 @@ unlock:
 out:
 	return ret;
 out_nomap:
+	mem_container_uncharge_page(page);
 	pte_unmap_unlock(page_table, ptl);
 	unlock_page(page);
 	page_cache_release(page);
@@ -2161,6 +2184,9 @@ static int do_anonymous_page(struct mm_s
 	if (!page)
 		goto oom;
 
+		if (mem_container_charge(page, mm))
+			goto oom_free_page;
+
 	entry = mk_pte(page, vma->vm_page_prot);
 	entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 
@@ -2178,8 +2204,11 @@ unlock:
 	pte_unmap_unlock(page_table, ptl);
 	return 0;
 release:
+	mem_container_uncharge_page(page);
 	page_cache_release(page);
 	goto unlock;
+oom_free_page:
+	__free_page(page);
 oom:
 	return VM_FAULT_OOM;
 }
@@ -2290,6 +2319,11 @@ static int __do_fault(struct mm_struct *
 
 	}
 
+	if (mem_container_charge(page, mm)) {
+		ret = VM_FAULT_OOM;
+		goto out;
+	}
+
 	page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
 
 	/*
@@ -2325,6 +2359,7 @@ static int __do_fault(struct mm_struct *
 		/* no need to invalidate: a not-present page won't be cached */
 		update_mmu_cache(vma, address, entry);
 	} else {
+		mem_container_uncharge_page(page);
 		if (anon)
 			page_cache_release(page);
 		else
diff -puN mm/migrate.c~mem-control-accounting mm/migrate.c
--- linux-2.6.23-rc2-mm2/mm/migrate.c~mem-control-accounting	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/migrate.c	2007-08-24 20:46:07.000000000 +0530
@@ -29,6 +29,7 @@
 #include <linux/mempolicy.h>
 #include <linux/vmalloc.h>
 #include <linux/security.h>
+#include <linux/memcontrol.h>
 
 #include "internal.h"
 
@@ -157,6 +158,11 @@ static void remove_migration_pte(struct 
  		return;
  	}
 
+	if (mem_container_charge(new, mm)) {
+		pte_unmap(ptep);
+		return;
+	}
+
  	ptl = pte_lockptr(mm, pmd);
  	spin_lock(ptl);
 	pte = *ptep;
diff -puN mm/page_alloc.c~mem-control-accounting mm/page_alloc.c
--- linux-2.6.23-rc2-mm2/mm/page_alloc.c~mem-control-accounting	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/page_alloc.c	2007-08-24 20:46:07.000000000 +0530
@@ -42,6 +42,7 @@
 #include <linux/backing-dev.h>
 #include <linux/fault-inject.h>
 #include <linux/page-isolation.h>
+#include <linux/memcontrol.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -1025,6 +1026,7 @@ static void fastcall free_hot_cold_page(
 
 	if (!PageHighMem(page))
 		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
+	page_assign_page_container(page, NULL);
 	arch_free_page(page, 0);
 	kernel_map_pages(page, 1, 0);
 
@@ -2654,6 +2656,7 @@ void __meminit memmap_init_zone(unsigned
 		set_page_links(page, zone, nid, pfn);
 		init_page_count(page);
 		reset_page_mapcount(page);
+		page_assign_page_container(page, NULL);
 		SetPageReserved(page);
 
 		/*
diff -puN mm/rmap.c~mem-control-accounting mm/rmap.c
--- linux-2.6.23-rc2-mm2/mm/rmap.c~mem-control-accounting	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/rmap.c	2007-08-24 20:46:07.000000000 +0530
@@ -48,6 +48,7 @@
 #include <linux/rcupdate.h>
 #include <linux/module.h>
 #include <linux/kallsyms.h>
+#include <linux/memcontrol.h>
 
 #include <asm/tlbflush.h>
 
@@ -550,8 +551,14 @@ void page_add_anon_rmap(struct page *pag
 	VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
 	if (atomic_inc_and_test(&page->_mapcount))
 		__page_set_anon_rmap(page, vma, address);
-	else
+	else {
 		__page_check_anon_rmap(page, vma, address);
+		/*
+		 * We unconditionally charged during prepare, we uncharge here
+		 * This takes care of balancing the reference counts
+		 */
+		mem_container_uncharge_page(page);
+	}
 }
 
 /*
@@ -582,6 +589,12 @@ void page_add_file_rmap(struct page *pag
 {
 	if (atomic_inc_and_test(&page->_mapcount))
 		__inc_zone_page_state(page, NR_FILE_MAPPED);
+	else
+		/*
+		 * We unconditionally charged during prepare, we uncharge here
+		 * This takes care of balancing the reference counts
+		 */
+		mem_container_uncharge_page(page);
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -642,6 +655,8 @@ void page_remove_rmap(struct page *page,
 			page_clear_dirty(page);
 			set_page_dirty(page);
 		}
+		mem_container_uncharge_page(page);
+
 		__dec_zone_page_state(page,
 				PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
 	}
diff -puN mm/swapfile.c~mem-control-accounting mm/swapfile.c
--- linux-2.6.23-rc2-mm2/mm/swapfile.c~mem-control-accounting	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/swapfile.c	2007-08-24 20:46:07.000000000 +0530
@@ -27,6 +27,7 @@
 #include <linux/mutex.h>
 #include <linux/capability.h>
 #include <linux/syscalls.h>
+#include <linux/memcontrol.h>
 
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
@@ -506,9 +507,12 @@ unsigned int count_swap_pages(int type, 
  * just let do_wp_page work it out if a write is requested later - to
  * force COW, vm_page_prot omits write permission from any private vma.
  */
-static void unuse_pte(struct vm_area_struct *vma, pte_t *pte,
+static int unuse_pte(struct vm_area_struct *vma, pte_t *pte,
 		unsigned long addr, swp_entry_t entry, struct page *page)
 {
+	if (mem_container_charge(page, vma->vm_mm))
+		return -ENOMEM;
+
 	inc_mm_counter(vma->vm_mm, anon_rss);
 	get_page(page);
 	set_pte_at(vma->vm_mm, addr, pte,
@@ -520,6 +524,7 @@ static void unuse_pte(struct vm_area_str
 	 * immediately swapped out again after swapon.
 	 */
 	activate_page(page);
+	return 1;
 }
 
 static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
@@ -529,7 +534,7 @@ static int unuse_pte_range(struct vm_are
 	pte_t swp_pte = swp_entry_to_pte(entry);
 	pte_t *pte;
 	spinlock_t *ptl;
-	int found = 0;
+	int ret = 0;
 
 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 	do {
@@ -538,13 +543,12 @@ static int unuse_pte_range(struct vm_are
 		 * Test inline before going to call unuse_pte.
 		 */
 		if (unlikely(pte_same(*pte, swp_pte))) {
-			unuse_pte(vma, pte++, addr, entry, page);
-			found = 1;
+			ret = unuse_pte(vma, pte++, addr, entry, page);
 			break;
 		}
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 	pte_unmap_unlock(pte - 1, ptl);
-	return found;
+	return ret;
 }
 
 static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
@@ -553,14 +557,16 @@ static inline int unuse_pmd_range(struct
 {
 	pmd_t *pmd;
 	unsigned long next;
+	int ret;
 
 	pmd = pmd_offset(pud, addr);
 	do {
 		next = pmd_addr_end(addr, end);
 		if (pmd_none_or_clear_bad(pmd))
 			continue;
-		if (unuse_pte_range(vma, pmd, addr, next, entry, page))
-			return 1;
+		ret = unuse_pte_range(vma, pmd, addr, next, entry, page);
+		if (ret)
+			return ret;
 	} while (pmd++, addr = next, addr != end);
 	return 0;
 }
@@ -571,14 +577,16 @@ static inline int unuse_pud_range(struct
 {
 	pud_t *pud;
 	unsigned long next;
+	int ret;
 
 	pud = pud_offset(pgd, addr);
 	do {
 		next = pud_addr_end(addr, end);
 		if (pud_none_or_clear_bad(pud))
 			continue;
-		if (unuse_pmd_range(vma, pud, addr, next, entry, page))
-			return 1;
+		ret = unuse_pmd_range(vma, pud, addr, next, entry, page);
+		if (ret)
+			return ret;
 	} while (pud++, addr = next, addr != end);
 	return 0;
 }
@@ -588,6 +596,7 @@ static int unuse_vma(struct vm_area_stru
 {
 	pgd_t *pgd;
 	unsigned long addr, end, next;
+	int ret;
 
 	if (page->mapping) {
 		addr = page_address_in_vma(page, vma);
@@ -605,8 +614,9 @@ static int unuse_vma(struct vm_area_stru
 		next = pgd_addr_end(addr, end);
 		if (pgd_none_or_clear_bad(pgd))
 			continue;
-		if (unuse_pud_range(vma, pgd, addr, next, entry, page))
-			return 1;
+		ret = unuse_pud_range(vma, pgd, addr, next, entry, page);
+		if (ret)
+			return ret;
 	} while (pgd++, addr = next, addr != end);
 	return 0;
 }
@@ -615,6 +625,7 @@ static int unuse_mm(struct mm_struct *mm
 				swp_entry_t entry, struct page *page)
 {
 	struct vm_area_struct *vma;
+	int ret = 0;
 
 	if (!down_read_trylock(&mm->mmap_sem)) {
 		/*
@@ -627,15 +638,11 @@ static int unuse_mm(struct mm_struct *mm
 		lock_page(page);
 	}
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
-		if (vma->anon_vma && unuse_vma(vma, entry, page))
+		if (vma->anon_vma && (ret = unuse_vma(vma, entry, page)))
 			break;
 	}
 	up_read(&mm->mmap_sem);
-	/*
-	 * Currently unuse_mm cannot fail, but leave error handling
-	 * at call sites for now, since we change it from time to time.
-	 */
-	return 0;
+	return ret;
 }
 
 /*
diff -puN mm/swap_state.c~mem-control-accounting mm/swap_state.c
--- linux-2.6.23-rc2-mm2/mm/swap_state.c~mem-control-accounting	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/swap_state.c	2007-08-24 20:46:07.000000000 +0530
@@ -17,6 +17,7 @@
 #include <linux/backing-dev.h>
 #include <linux/pagevec.h>
 #include <linux/migrate.h>
+#include <linux/memcontrol.h>
 
 #include <asm/pgtable.h>
 
@@ -80,6 +81,11 @@ static int __add_to_swap_cache(struct pa
 	BUG_ON(PagePrivate(page));
 	error = radix_tree_preload(gfp_mask);
 	if (!error) {
+
+		error = mem_container_charge(page, current->mm);
+		if (error)
+			goto out;
+
 		write_lock_irq(&swapper_space.tree_lock);
 		error = radix_tree_insert(&swapper_space.page_tree,
 						entry.val, page);
@@ -89,10 +95,13 @@ static int __add_to_swap_cache(struct pa
 			set_page_private(page, entry.val);
 			total_swapcache_pages++;
 			__inc_zone_page_state(page, NR_FILE_PAGES);
-		}
+		} else
+			mem_container_uncharge_page(page);
+
 		write_unlock_irq(&swapper_space.tree_lock);
 		radix_tree_preload_end();
 	}
+out:
 	return error;
 }
 
@@ -132,6 +141,7 @@ void __delete_from_swap_cache(struct pag
 	BUG_ON(PageWriteback(page));
 	BUG_ON(PagePrivate(page));
 
+	mem_container_uncharge_page(page);
 	radix_tree_delete(&swapper_space.page_tree, page_private(page));
 	set_page_private(page, 0);
 	ClearPageSwapCache(page);
_

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

[-mm PATCH 5/10] Memory controller task migration (v7)

[Balbir Singh]

Allow tasks to migrate from one container to the other. We migrate
mm_struct's mem_container only when the thread group id migrates.


Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

 mm/memcontrol.c |   35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff -puN mm/memcontrol.c~mem-control-task-migration mm/memcontrol.c
--- linux-2.6.23-rc2-mm2/mm/memcontrol.c~mem-control-task-migration	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/memcontrol.c	2007-08-24 20:46:07.000000000 +0530
@@ -326,11 +326,46 @@ static int mem_container_populate(struct
 					ARRAY_SIZE(mem_container_files));
 }
 
+static void mem_container_move_task(struct container_subsys *ss,
+				struct container *cont,
+				struct container *old_cont,
+				struct task_struct *p)
+{
+	struct mm_struct *mm;
+	struct mem_container *mem, *old_mem;
+
+	mm = get_task_mm(p);
+	if (mm == NULL)
+		return;
+
+	mem = mem_container_from_cont(cont);
+	old_mem = mem_container_from_cont(old_cont);
+
+	if (mem == old_mem)
+		goto out;
+
+	/*
+	 * Only thread group leaders are allowed to migrate, the mm_struct is
+	 * in effect owned by the leader
+	 */
+	if (p->tgid != p->pid)
+		goto out;
+
+	css_get(&mem->css);
+	rcu_assign_pointer(mm->mem_container, mem);
+	css_put(&old_mem->css);
+
+out:
+	mmput(mm);
+	return;
+}
+
 struct container_subsys mem_container_subsys = {
 	.name = "memory",
 	.subsys_id = mem_container_subsys_id,
 	.create = mem_container_create,
 	.destroy = mem_container_destroy,
 	.populate = mem_container_populate,
+	.attach = mem_container_move_task,
 	.early_init = 1,
 };
_

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

Re: [-mm PATCH 5/10] Memory controller task migration (v7)

[YAMAMOTO Takashi]

> Allow tasks to migrate from one container to the other. We migrate
> mm_struct's mem_container only when the thread group id migrates.

> +	/*
> +	 * Only thread group leaders are allowed to migrate, the mm_struct is
> +	 * in effect owned by the leader
> +	 */
> +	if (p->tgid != p->pid)
> +		goto out;

does it mean that you can't move a process between containers
once its thread group leader exited?

YAMAMOTO Takashi

Re: [-mm PATCH 5/10] Memory controller task migration (v7)

[Balbir Singh]

YAMAMOTO Takashi wrote:
>> Allow tasks to migrate from one container to the other. We migrate
>> mm_struct's mem_container only when the thread group id migrates.
> 
>> +	/*
>> +	 * Only thread group leaders are allowed to migrate, the mm_struct is
>> +	 * in effect owned by the leader
>> +	 */
>> +	if (p->tgid != p->pid)
>> +		goto out;
> 
> does it mean that you can't move a process between containers
> once its thread group leader exited?
> 
> YAMAMOTO Takashi


Hi,

Good catch! Currently, we treat the mm as owned by the thread group leader.
But this policy can be easily adapted to any other desired policy.
Would you like to see it change to something else?

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

Re: [-mm PATCH 5/10] Memory controller task migration (v7)

[YAMAMOTO Takashi]

> YAMAMOTO Takashi wrote:
> >> Allow tasks to migrate from one container to the other. We migrate
> >> mm_struct's mem_container only when the thread group id migrates.
> > 
> >> +	/*
> >> +	 * Only thread group leaders are allowed to migrate, the mm_struct is
> >> +	 * in effect owned by the leader
> >> +	 */
> >> +	if (p->tgid != p->pid)
> >> +		goto out;
> > 
> > does it mean that you can't move a process between containers
> > once its thread group leader exited?
> > 
> > YAMAMOTO Takashi
> 
> 
> Hi,
> 
> Good catch! Currently, we treat the mm as owned by the thread group leader.
> But this policy can be easily adapted to any other desired policy.
> Would you like to see it change to something else?
> 
> -- 
> 	Warm Regards,
> 	Balbir Singh
> 	Linux Technology Center
> 	IBM, ISTL

although i have no good idea right now, something which allows
to move a process with its thread group leader dead would be better.

YAMAMOTO Takashi

Re: [-mm PATCH 5/10] Memory controller task migration (v7)

[Paul Menage]

On 8/28/07, YAMAMOTO Takashi <yamamoto@valinux.co.jp> wrote:
>
> although i have no good idea right now, something which allows
> to move a process with its thread group leader dead would be better.
>

One way I was thinking of approaching this problem was slightly different:

- every mm always has an "owning" task. Initially that will be the
thread that creates the mm

- if the owning thread exits or execs and *isn't* the last user of the
mm, then we may need to find a new owner for the mm:

1) My guess is that typically the thread that created the mm will also
be the last user of the mm - if this is the case, then in the normal
case we don't need to find a new owner.

2) If we do need a new owner, first look amongst the other threads in
the process (cheap, should find another user of the mm quickly)

3) next look in the child and parent threads (more expensive, but rarer)

4) if necessary, scan the entire thread list (expensive, but should
never be needed in general use)

The advantage of this is that we don't then need to have a memory
container pointer in the mm - we can just use the memory container of
the mm's owner.

With just a single container type needing to be tied to an mm, this
isn't a huge advantage since we're just replacing one pointer (memory
container) with another (owning task) and have similar levels of
complexity for both. But if we have multiple container subsystems that
need to be tied to a particular mm then they can both use the mm owner
pointer.

E.g. I want to add a swap container subsystem that restricts which
swap devices a group of processes can swap to, and how many pages they
can put into swap. And I want to be able to run this independently of
the in-memory page accounting subsystem. Having a task owner pointer
in the mm allows these to be indpendent subsystems, and (I believe)
isn't any more complex than the work involved to support moving an mm
whose thread group leader has exited or execd.

Paul

[-mm PATCH 6/10] Memory controller add per container LRU and reclaim (v7)

[Balbir Singh]

Changelog since v3
1. Added reclaim retry logic to avoid being OOM'ed due to pages from
   swap cache (coming in due to reclaim) don't overwhelm the container.

Changelog
1. Fix probable NULL pointer dereference based on review comments
   by YAMAMOTO Takashi

Add the page_container to the per container LRU. The reclaim algorithm has been
modified to make the isolate_lru_pages() as a pluggable component. The
scan_control data structure now accepts the container on behalf of which
reclaims are carried out. try_to_free_pages() has been extended to become
container aware.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

 include/linux/memcontrol.h  |   12 +++
 include/linux/res_counter.h |   23 +++++++
 include/linux/swap.h        |    3 
 mm/memcontrol.c             |  135 +++++++++++++++++++++++++++++++++++++++++++-
 mm/swap.c                   |    2 
 mm/vmscan.c                 |  126 ++++++++++++++++++++++++++++++++---------
 6 files changed, 275 insertions(+), 26 deletions(-)

diff -puN include/linux/memcontrol.h~mem-control-lru-and-reclaim include/linux/memcontrol.h
--- linux-2.6.23-rc2-mm2/include/linux/memcontrol.h~mem-control-lru-and-reclaim	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/memcontrol.h	2007-08-24 20:46:07.000000000 +0530
@@ -32,6 +32,13 @@ extern void page_assign_page_container(s
 extern struct page_container *page_get_page_container(struct page *page);
 extern int mem_container_charge(struct page *page, struct mm_struct *mm);
 extern void mem_container_uncharge(struct page_container *pc);
+extern void mem_container_move_lists(struct page_container *pc, bool active);
+extern unsigned long mem_container_isolate_pages(unsigned long nr_to_scan,
+					struct list_head *dst,
+					unsigned long *scanned, int order,
+					int mode, struct zone *z,
+					struct mem_container *mem_cont,
+					int active);
 
 static inline void mem_container_uncharge_page(struct page *page)
 {
@@ -71,6 +78,11 @@ static inline void mem_container_uncharg
 {
 }
 
+static inline void mem_container_move_lists(struct page_container *pc,
+						bool active)
+{
+}
+
 #endif /* CONFIG_CONTAINER_MEM_CONT */
 
 #endif /* _LINUX_MEMCONTROL_H */
diff -puN include/linux/res_counter.h~mem-control-lru-and-reclaim include/linux/res_counter.h
--- linux-2.6.23-rc2-mm2/include/linux/res_counter.h~mem-control-lru-and-reclaim	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/res_counter.h	2007-08-24 20:46:07.000000000 +0530
@@ -99,4 +99,27 @@ int res_counter_charge(struct res_counte
 void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val);
 void res_counter_uncharge(struct res_counter *counter, unsigned long val);
 
+static inline bool res_counter_limit_check_locked(struct res_counter *cnt)
+{
+	if (cnt->usage < cnt->limit)
+		return true;
+
+	return false;
+}
+
+/*
+ * Helper function to detect if the container is within it's limit or
+ * not. It's currently called from container_rss_prepare()
+ */
+static inline bool res_counter_check_under_limit(struct res_counter *cnt)
+{
+	bool ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cnt->lock, flags);
+	ret = res_counter_limit_check_locked(cnt);
+	spin_unlock_irqrestore(&cnt->lock, flags);
+	return ret;
+}
+
 #endif
diff -puN include/linux/swap.h~mem-control-lru-and-reclaim include/linux/swap.h
--- linux-2.6.23-rc2-mm2/include/linux/swap.h~mem-control-lru-and-reclaim	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/swap.h	2007-08-24 20:46:07.000000000 +0530
@@ -6,6 +6,7 @@
 #include <linux/mmzone.h>
 #include <linux/list.h>
 #include <linux/sched.h>
+#include <linux/memcontrol.h>
 
 #include <asm/atomic.h>
 #include <asm/page.h>
@@ -191,6 +192,8 @@ extern void swap_setup(void);
 /* linux/mm/vmscan.c */
 extern unsigned long try_to_free_pages(struct zone **zones, int order,
 					gfp_t gfp_mask);
+extern unsigned long try_to_free_mem_container_pages(struct mem_container *mem);
+extern int __isolate_lru_page(struct page *page, int mode);
 extern unsigned long shrink_all_memory(unsigned long nr_pages);
 extern int vm_swappiness;
 extern int remove_mapping(struct address_space *mapping, struct page *page);
diff -puN mm/memcontrol.c~mem-control-lru-and-reclaim mm/memcontrol.c
--- linux-2.6.23-rc2-mm2/mm/memcontrol.c~mem-control-lru-and-reclaim	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/memcontrol.c	2007-08-24 20:46:07.000000000 +0530
@@ -24,8 +24,12 @@
 #include <linux/page-flags.h>
 #include <linux/bit_spinlock.h>
 #include <linux/rcupdate.h>
+#include <linux/swap.h>
+#include <linux/spinlock.h>
+#include <linux/fs.h>
 
 struct container_subsys mem_container_subsys;
+static const int MEM_CONTAINER_RECLAIM_RETRIES = 5;
 
 /*
  * The memory controller data structure. The memory controller controls both
@@ -51,6 +55,10 @@ struct mem_container {
 	 */
 	struct list_head active_list;
 	struct list_head inactive_list;
+	/*
+	 * spin_lock to protect the per container LRU
+	 */
+	spinlock_t lru_lock;
 };
 
 /*
@@ -141,6 +149,94 @@ void __always_inline unlock_page_contain
 	bit_spin_unlock(PAGE_CONTAINER_LOCK_BIT, &page->page_container);
 }
 
+void __mem_container_move_lists(struct page_container *pc, bool active)
+{
+	if (active)
+		list_move(&pc->lru, &pc->mem_container->active_list);
+	else
+		list_move(&pc->lru, &pc->mem_container->inactive_list);
+}
+
+/*
+ * This routine assumes that the appropriate zone's lru lock is already held
+ */
+void mem_container_move_lists(struct page_container *pc, bool active)
+{
+	struct mem_container *mem;
+	if (!pc)
+		return;
+
+	mem = pc->mem_container;
+
+	spin_lock(&mem->lru_lock);
+	__mem_container_move_lists(pc, active);
+	spin_unlock(&mem->lru_lock);
+}
+
+unsigned long mem_container_isolate_pages(unsigned long nr_to_scan,
+					struct list_head *dst,
+					unsigned long *scanned, int order,
+					int mode, struct zone *z,
+					struct mem_container *mem_cont,
+					int active)
+{
+	unsigned long nr_taken = 0;
+	struct page *page;
+	unsigned long scan;
+	LIST_HEAD(pc_list);
+	struct list_head *src;
+	struct page_container *pc;
+
+	if (active)
+		src = &mem_cont->active_list;
+	else
+		src = &mem_cont->inactive_list;
+
+	spin_lock(&mem_cont->lru_lock);
+	for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
+		pc = list_entry(src->prev, struct page_container, lru);
+		page = pc->page;
+		VM_BUG_ON(!pc);
+
+		if (PageActive(page) && !active) {
+			__mem_container_move_lists(pc, true);
+			scan--;
+			continue;
+		}
+		if (!PageActive(page) && active) {
+			__mem_container_move_lists(pc, false);
+			scan--;
+			continue;
+		}
+
+		/*
+		 * Reclaim, per zone
+		 * TODO: make the active/inactive lists per zone
+		 */
+		if (page_zone(page) != z)
+			continue;
+
+		/*
+		 * Check if the meta page went away from under us
+		 */
+		if (!list_empty(&pc->lru))
+			list_move(&pc->lru, &pc_list);
+		else
+			continue;
+
+		if (__isolate_lru_page(page, mode) == 0) {
+			list_move(&page->lru, dst);
+			nr_taken++;
+		}
+	}
+
+	list_splice(&pc_list, src);
+	spin_unlock(&mem_cont->lru_lock);
+
+	*scanned = scan;
+	return nr_taken;
+}
+
 /*
  * Charge the memory controller for page usage.
  * Return
@@ -151,6 +247,8 @@ int mem_container_charge(struct page *pa
 {
 	struct mem_container *mem;
 	struct page_container *pc, *race_pc;
+	unsigned long flags;
+	unsigned long nr_retries = MEM_CONTAINER_RECLAIM_RETRIES;
 
 	/*
 	 * Should page_container's go to their own slab?
@@ -197,7 +295,32 @@ int mem_container_charge(struct page *pa
 	 * If we created the page_container, we should free it on exceeding
 	 * the container limit.
 	 */
-	if (res_counter_charge(&mem->res, 1)) {
+	while (res_counter_charge(&mem->res, 1)) {
+		if (try_to_free_mem_container_pages(mem))
+			continue;
+
+		/*
+ 		 * try_to_free_mem_container_pages() might not give us a full
+ 		 * picture of reclaim. Some pages are reclaimed and might be
+ 		 * moved to swap cache or just unmapped from the container.
+ 		 * Check the limit again to see if the reclaim reduced the
+ 		 * current usage of the container before giving up
+ 		 */
+		if (res_counter_check_under_limit(&mem->res))
+			continue;
+			/*
+			 * Since we control both RSS and cache, we end up with a
+			 * very interesting scenario where we end up reclaiming
+			 * memory (essentially RSS), since the memory is pushed
+			 * to swap cache, we eventually end up adding those
+			 * pages back to our list. Hence we give ourselves a
+			 * few chances before we fail
+			 */
+		else if (nr_retries--) {
+			congestion_wait(WRITE, HZ/10);
+			continue;
+		}
+
 		css_put(&mem->css);
 		goto free_pc;
 	}
@@ -221,6 +344,10 @@ int mem_container_charge(struct page *pa
 	pc->page = page;
 	page_assign_page_container(page, pc);
 
+	spin_lock_irqsave(&mem->lru_lock, flags);
+	list_add(&pc->lru, &mem->active_list);
+	spin_unlock_irqrestore(&mem->lru_lock, flags);
+
 done:
 	unlock_page_container(page);
 	return 0;
@@ -240,6 +367,7 @@ void mem_container_uncharge(struct page_
 {
 	struct mem_container *mem;
 	struct page *page;
+	unsigned long flags;
 
 	if (!pc)
 		return;
@@ -252,6 +380,10 @@ void mem_container_uncharge(struct page_
 		page_assign_page_container(page, NULL);
 		unlock_page_container(page);
 		res_counter_uncharge(&mem->res, 1);
+
+ 		spin_lock_irqsave(&mem->lru_lock, flags);
+ 		list_del_init(&pc->lru);
+ 		spin_unlock_irqrestore(&mem->lru_lock, flags);
 		kfree(pc);
 	}
 }
@@ -310,6 +442,7 @@ mem_container_create(struct container_su
 	res_counter_init(&mem->res);
 	INIT_LIST_HEAD(&mem->active_list);
 	INIT_LIST_HEAD(&mem->inactive_list);
+	spin_lock_init(&mem->lru_lock);
 	return &mem->css;
 }
 
diff -puN mm/swap.c~mem-control-lru-and-reclaim mm/swap.c
--- linux-2.6.23-rc2-mm2/mm/swap.c~mem-control-lru-and-reclaim	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/swap.c	2007-08-24 20:46:07.000000000 +0530
@@ -29,6 +29,7 @@
 #include <linux/percpu.h>
 #include <linux/cpu.h>
 #include <linux/notifier.h>
+#include <linux/memcontrol.h>
 
 /* How many pages do we try to swap or page in/out together? */
 int page_cluster;
@@ -146,6 +147,7 @@ void fastcall activate_page(struct page 
 		SetPageActive(page);
 		add_page_to_active_list(zone, page);
 		__count_vm_event(PGACTIVATE);
+		mem_container_move_lists(page_get_page_container(page), true);
 	}
 	spin_unlock_irq(&zone->lru_lock);
 }
diff -puN mm/vmscan.c~mem-control-lru-and-reclaim mm/vmscan.c
--- linux-2.6.23-rc2-mm2/mm/vmscan.c~mem-control-lru-and-reclaim	2007-08-24 20:46:07.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/vmscan.c	2007-08-24 20:46:07.000000000 +0530
@@ -39,6 +39,7 @@
 #include <linux/delay.h>
 #include <linux/kthread.h>
 #include <linux/freezer.h>
+#include <linux/memcontrol.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -70,6 +71,15 @@ struct scan_control {
 	int all_unreclaimable;
 
 	int order;
+
+	/* Which container do we reclaim from */
+	struct mem_container *mem_container;
+
+	/* Pluggable isolate pages callback */
+	unsigned long (*isolate_pages)(unsigned long nr, struct list_head *dst,
+			unsigned long *scanned, int order, int mode,
+			struct zone *z, struct mem_container *mem_cont,
+			int active);
 };
 
 #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
@@ -634,7 +644,7 @@ keep:
  *
  * returns 0 on success, -ve errno on failure.
  */
-static int __isolate_lru_page(struct page *page, int mode)
+int __isolate_lru_page(struct page *page, int mode)
 {
 	int ret = -EINVAL;
 
@@ -768,6 +778,21 @@ static unsigned long isolate_lru_pages(u
 	return nr_taken;
 }
 
+static unsigned long isolate_pages_global(unsigned long nr,
+					struct list_head *dst,
+					unsigned long *scanned, int order,
+					int mode, struct zone *z,
+					struct mem_container *mem_cont,
+					int active)
+{
+	if (active)
+		return isolate_lru_pages(nr, &z->active_list, dst,
+						scanned, order, mode);
+	else
+		return isolate_lru_pages(nr, &z->inactive_list, dst,
+						scanned, order, mode);
+}
+
 /*
  * clear_active_flags() is a helper for shrink_active_list(), clearing
  * any active bits from the pages in the list.
@@ -809,11 +834,11 @@ static unsigned long shrink_inactive_lis
 		unsigned long nr_freed;
 		unsigned long nr_active;
 
-		nr_taken = isolate_lru_pages(sc->swap_cluster_max,
-			     &zone->inactive_list,
+		nr_taken = sc->isolate_pages(sc->swap_cluster_max,
 			     &page_list, &nr_scan, sc->order,
 			     (sc->order > PAGE_ALLOC_COSTLY_ORDER)?
-					     ISOLATE_BOTH : ISOLATE_INACTIVE);
+					     ISOLATE_BOTH : ISOLATE_INACTIVE,
+				zone, sc->mem_container, 0);
 		nr_active = clear_active_flags(&page_list);
 		__count_vm_events(PGDEACTIVATE, nr_active);
 
@@ -1026,8 +1051,9 @@ force_reclaim_mapped:
 
 	lru_add_drain();
 	spin_lock_irq(&zone->lru_lock);
-	pgmoved = isolate_lru_pages(nr_pages, &zone->active_list,
-			    &l_hold, &pgscanned, sc->order, ISOLATE_ACTIVE);
+	pgmoved = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order,
+					ISOLATE_ACTIVE, zone,
+					sc->mem_container, 1);
 	zone->pages_scanned += pgscanned;
 	__mod_zone_page_state(zone, NR_ACTIVE, -pgmoved);
 	spin_unlock_irq(&zone->lru_lock);
@@ -1062,6 +1088,7 @@ force_reclaim_mapped:
 		ClearPageActive(page);
 
 		list_move(&page->lru, &zone->inactive_list);
+		mem_container_move_lists(page_get_page_container(page), false);
 		pgmoved++;
 		if (!pagevec_add(&pvec, page)) {
 			__mod_zone_page_state(zone, NR_INACTIVE, pgmoved);
@@ -1090,6 +1117,7 @@ force_reclaim_mapped:
 		SetPageLRU(page);
 		VM_BUG_ON(!PageActive(page));
 		list_move(&page->lru, &zone->active_list);
+		mem_container_move_lists(page_get_page_container(page), true);
 		pgmoved++;
 		if (!pagevec_add(&pvec, page)) {
 			__mod_zone_page_state(zone, NR_ACTIVE, pgmoved);
@@ -1221,7 +1249,8 @@ static unsigned long shrink_zones(int pr
  * holds filesystem locks which prevent writeout this might not work, and the
  * allocation attempt will fail.
  */
-unsigned long try_to_free_pages(struct zone **zones, int order, gfp_t gfp_mask)
+unsigned long do_try_to_free_pages(struct zone **zones, gfp_t gfp_mask,
+					struct scan_control *sc)
 {
 	int priority;
 	int ret = 0;
@@ -1230,14 +1259,6 @@ unsigned long try_to_free_pages(struct z
 	struct reclaim_state *reclaim_state = current->reclaim_state;
 	unsigned long lru_pages = 0;
 	int i;
-	struct scan_control sc = {
-		.gfp_mask = gfp_mask,
-		.may_writepage = !laptop_mode,
-		.swap_cluster_max = SWAP_CLUSTER_MAX,
-		.may_swap = 1,
-		.swappiness = vm_swappiness,
-		.order = order,
-	};
 
 	delay_swap_prefetch();
 	count_vm_event(ALLOCSTALL);
@@ -1253,17 +1274,22 @@ unsigned long try_to_free_pages(struct z
 	}
 
 	for (priority = DEF_PRIORITY; priority >= 0; priority--) {
-		sc.nr_scanned = 0;
+		sc->nr_scanned = 0;
 		if (!priority)
 			disable_swap_token();
-		nr_reclaimed += shrink_zones(priority, zones, &sc);
-		shrink_slab(sc.nr_scanned, gfp_mask, lru_pages);
+		nr_reclaimed += shrink_zones(priority, zones, sc);
+		/*
+		 * Don't shrink slabs when reclaiming memory from
+		 * over limit containers
+		 */
+		if (sc->mem_container == NULL)
+			shrink_slab(sc->nr_scanned, gfp_mask, lru_pages);
 		if (reclaim_state) {
 			nr_reclaimed += reclaim_state->reclaimed_slab;
 			reclaim_state->reclaimed_slab = 0;
 		}
-		total_scanned += sc.nr_scanned;
-		if (nr_reclaimed >= sc.swap_cluster_max) {
+		total_scanned += sc->nr_scanned;
+		if (nr_reclaimed >= sc->swap_cluster_max) {
 			ret = 1;
 			goto out;
 		}
@@ -1275,18 +1301,18 @@ unsigned long try_to_free_pages(struct z
 		 * that's undesirable in laptop mode, where we *want* lumpy
 		 * writeout.  So in laptop mode, write out the whole world.
 		 */
-		if (total_scanned > sc.swap_cluster_max +
-					sc.swap_cluster_max / 2) {
+		if (total_scanned > sc->swap_cluster_max +
+					sc->swap_cluster_max / 2) {
 			wakeup_pdflush(laptop_mode ? 0 : total_scanned);
-			sc.may_writepage = 1;
+			sc->may_writepage = 1;
 		}
 
 		/* Take a nap, wait for some writeback to complete */
-		if (sc.nr_scanned && priority < DEF_PRIORITY - 2)
+		if (sc->nr_scanned && priority < DEF_PRIORITY - 2)
 			congestion_wait(WRITE, HZ/10);
 	}
 	/* top priority shrink_caches still had more to do? don't OOM, then */
-	if (!sc.all_unreclaimable)
+	if (!sc->all_unreclaimable && sc->mem_container == NULL)
 		ret = 1;
 out:
 	/*
@@ -1309,6 +1335,54 @@ out:
 	return ret;
 }
 
+unsigned long try_to_free_pages(struct zone **zones, int order, gfp_t gfp_mask)
+{
+	struct scan_control sc = {
+		.gfp_mask = gfp_mask,
+		.may_writepage = !laptop_mode,
+		.swap_cluster_max = SWAP_CLUSTER_MAX,
+		.may_swap = 1,
+		.swappiness = vm_swappiness,
+		.order = order,
+		.mem_container = NULL,
+		.isolate_pages = isolate_pages_global,
+	};
+
+	return do_try_to_free_pages(zones, gfp_mask, &sc);
+}
+
+#ifdef CONFIG_CONTAINER_MEM_CONT
+
+#ifdef CONFIG_HIGHMEM
+#define ZONE_USERPAGES ZONE_HIGHMEM
+#else
+#define ZONE_USERPAGES ZONE_NORMAL
+#endif
+
+unsigned long try_to_free_mem_container_pages(struct mem_container *mem_cont)
+{
+	struct scan_control sc = {
+		.gfp_mask = GFP_KERNEL,
+		.may_writepage = !laptop_mode,
+		.may_swap = 1,
+		.swap_cluster_max = SWAP_CLUSTER_MAX,
+		.swappiness = vm_swappiness,
+		.order = 1,
+		.mem_container = mem_cont,
+		.isolate_pages = mem_container_isolate_pages,
+	};
+	int node;
+	struct zone **zones;
+
+	for_each_online_node(node) {
+		zones = NODE_DATA(node)->node_zonelists[ZONE_USERPAGES].zones;
+		if (do_try_to_free_pages(zones, sc.gfp_mask, &sc))
+			return 1;
+	}
+	return 0;
+}
+#endif
+
 /*
  * For kswapd, balance_pgdat() will work across all this node's zones until
  * they are all at pages_high.
@@ -1344,6 +1418,8 @@ static unsigned long balance_pgdat(pg_da
 		.swap_cluster_max = SWAP_CLUSTER_MAX,
 		.swappiness = vm_swappiness,
 		.order = order,
+		.mem_container = NULL,
+		.isolate_pages = isolate_pages_global,
 	};
 	/*
 	 * temp_priority is used to remember the scanning priority at which
_

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

[-mm PATCH 7/10] Memory controller OOM handling (v7)

[Balbir Singh]

From: Pavel Emelianov <xemul@openvz.org>

Out of memory handling for containers over their limit. A task from the
container over limit is chosen using the existing OOM logic and killed.

TODO:
1. As discussed in the OLS BOF session, consider implementing a user
space policy for OOM handling.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

 include/linux/memcontrol.h |    1 +
 mm/memcontrol.c            |    1 +
 mm/oom_kill.c              |   42 ++++++++++++++++++++++++++++++++++++++----
 3 files changed, 40 insertions(+), 4 deletions(-)

diff -puN include/linux/memcontrol.h~mem-control-out-of-memory include/linux/memcontrol.h
--- linux-2.6.23-rc2-mm2/include/linux/memcontrol.h~mem-control-out-of-memory	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/memcontrol.h	2007-08-24 20:46:08.000000000 +0530
@@ -39,6 +39,7 @@ extern unsigned long mem_container_isola
 					int mode, struct zone *z,
 					struct mem_container *mem_cont,
 					int active);
+extern void mem_container_out_of_memory(struct mem_container *mem);
 
 static inline void mem_container_uncharge_page(struct page *page)
 {
diff -puN mm/memcontrol.c~mem-control-out-of-memory mm/memcontrol.c
--- linux-2.6.23-rc2-mm2/mm/memcontrol.c~mem-control-out-of-memory	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/memcontrol.c	2007-08-24 20:46:08.000000000 +0530
@@ -322,6 +322,7 @@ int mem_container_charge(struct page *pa
 		}
 
 		css_put(&mem->css);
+		mem_container_out_of_memory(mem);
 		goto free_pc;
 	}
 
diff -puN mm/oom_kill.c~mem-control-out-of-memory mm/oom_kill.c
--- linux-2.6.23-rc2-mm2/mm/oom_kill.c~mem-control-out-of-memory	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/oom_kill.c	2007-08-24 20:46:08.000000000 +0530
@@ -25,6 +25,7 @@
 #include <linux/cpuset.h>
 #include <linux/module.h>
 #include <linux/notifier.h>
+#include <linux/memcontrol.h>
 
 int sysctl_panic_on_oom;
 /* #define DEBUG */
@@ -48,7 +49,8 @@ int sysctl_panic_on_oom;
  *    of least surprise ... (be careful when you change it)
  */
 
-unsigned long badness(struct task_struct *p, unsigned long uptime)
+unsigned long badness(struct task_struct *p, unsigned long uptime,
+			struct mem_container *mem)
 {
 	unsigned long points, cpu_time, run_time, s;
 	struct mm_struct *mm;
@@ -61,6 +63,13 @@ unsigned long badness(struct task_struct
 		return 0;
 	}
 
+#ifdef CONFIG_CONTAINER_MEM_CONT
+	if (mem != NULL && mm->mem_container != mem) {
+		task_unlock(p);
+		return 0;
+	}
+#endif
+
 	/*
 	 * The memory size of the process is the basis for the badness.
 	 */
@@ -198,7 +207,8 @@ static inline int constrained_alloc(stru
  *
  * (not docbooked, we don't want this one cluttering up the manual)
  */
-static struct task_struct *select_bad_process(unsigned long *ppoints)
+static struct task_struct *select_bad_process(unsigned long *ppoints,
+						struct mem_container *mem)
 {
 	struct task_struct *g, *p;
 	struct task_struct *chosen = NULL;
@@ -252,7 +262,7 @@ static struct task_struct *select_bad_pr
 		if (p->oomkilladj == OOM_DISABLE)
 			continue;
 
-		points = badness(p, uptime.tv_sec);
+		points = badness(p, uptime.tv_sec, mem);
 		if (points > *ppoints || !chosen) {
 			chosen = p;
 			*ppoints = points;
@@ -364,6 +374,30 @@ static int oom_kill_process(struct task_
 	return oom_kill_task(p);
 }
 
+#ifdef CONFIG_CONTAINER_MEM_CONT
+void mem_container_out_of_memory(struct mem_container *mem)
+{
+	unsigned long points = 0;
+	struct task_struct *p;
+
+	container_lock();
+	rcu_read_lock();
+retry:
+	p = select_bad_process(&points, mem);
+	if (PTR_ERR(p) == -1UL)
+		goto out;
+
+	if (!p)
+		p = current;
+
+	if (oom_kill_process(p, points, "Memory container out of memory"))
+		goto retry;
+out:
+	rcu_read_unlock();
+	container_unlock();
+}
+#endif
+
 static BLOCKING_NOTIFIER_HEAD(oom_notify_list);
 
 int register_oom_notifier(struct notifier_block *nb)
@@ -436,7 +470,7 @@ retry:
 		 * Rambo mode: Shoot down a process and hope it solves whatever
 		 * issues we may have.
 		 */
-		p = select_bad_process(&points);
+		p = select_bad_process(&points, NULL);
 
 		if (PTR_ERR(p) == -1UL)
 			goto out;
_

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

[-mm PATCH 8/10] Memory controller add switch to control what type of pages to limit (v7)

[Balbir Singh]

Choose if we want cached pages to be accounted or not. By default both
are accounted for. A new set of tunables are added.

echo -n 1 > mem_control_type

switches the accounting to account for only mapped pages

echo -n 3 > mem_control_type

switches the behaviour back

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

 include/linux/memcontrol.h |    9 ++++
 mm/filemap.c               |    2 
 mm/memcontrol.c            |   92 +++++++++++++++++++++++++++++++++++++++++++++
 mm/swap_state.c            |    2 
 4 files changed, 103 insertions(+), 2 deletions(-)

diff -puN include/linux/memcontrol.h~mem-control-choose-rss-vs-rss-and-pagecache include/linux/memcontrol.h
--- linux-2.6.23-rc2-mm2/include/linux/memcontrol.h~mem-control-choose-rss-vs-rss-and-pagecache	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/memcontrol.h	2007-08-24 20:46:08.000000000 +0530
@@ -20,6 +20,8 @@
 #ifndef _LINUX_MEMCONTROL_H
 #define _LINUX_MEMCONTROL_H
 
+#include <linux/mm.h>
+
 struct mem_container;
 struct page_container;
 
@@ -40,6 +42,7 @@ extern unsigned long mem_container_isola
 					struct mem_container *mem_cont,
 					int active);
 extern void mem_container_out_of_memory(struct mem_container *mem);
+extern int mem_container_cache_charge(struct page *page, struct mm_struct *mm);
 
 static inline void mem_container_uncharge_page(struct page *page)
 {
@@ -84,6 +87,12 @@ static inline void mem_container_move_li
 {
 }
 
+static inline int mem_container_cache_charge(struct page *page,
+						struct mm_struct *mm)
+{
+	return 0;
+}
+
 #endif /* CONFIG_CONTAINER_MEM_CONT */
 
 #endif /* _LINUX_MEMCONTROL_H */
diff -puN mm/filemap.c~mem-control-choose-rss-vs-rss-and-pagecache mm/filemap.c
--- linux-2.6.23-rc2-mm2/mm/filemap.c~mem-control-choose-rss-vs-rss-and-pagecache	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/filemap.c	2007-08-24 20:46:08.000000000 +0530
@@ -445,7 +445,7 @@ int add_to_page_cache(struct page *page,
 
 	if (error == 0) {
 
-		error = mem_container_charge(page, current->mm);
+		error = mem_container_cache_charge(page, current->mm);
 		if (error)
 			goto out;
 
diff -puN mm/memcontrol.c~mem-control-choose-rss-vs-rss-and-pagecache mm/memcontrol.c
--- linux-2.6.23-rc2-mm2/mm/memcontrol.c~mem-control-choose-rss-vs-rss-and-pagecache	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/memcontrol.c	2007-08-24 20:46:08.000000000 +0530
@@ -28,6 +28,8 @@
 #include <linux/spinlock.h>
 #include <linux/fs.h>
 
+#include <asm/uaccess.h>
+
 struct container_subsys mem_container_subsys;
 static const int MEM_CONTAINER_RECLAIM_RETRIES = 5;
 
@@ -59,6 +61,7 @@ struct mem_container {
 	 * spin_lock to protect the per container LRU
 	 */
 	spinlock_t lru_lock;
+	unsigned long control_type;	/* control RSS or RSS+Pagecache */
 };
 
 /*
@@ -81,6 +84,15 @@ struct page_container {
 					/* mapped and cached states     */
 };
 
+enum {
+	MEM_CONTAINER_TYPE_UNSPEC = 0,
+	MEM_CONTAINER_TYPE_MAPPED,
+	MEM_CONTAINER_TYPE_CACHED,
+	MEM_CONTAINER_TYPE_ALL,
+	MEM_CONTAINER_TYPE_MAX,
+} mem_control_type;
+
+static struct mem_container init_mem_container;
 
 static inline
 struct mem_container *mem_container_from_cont(struct container *cont)
@@ -361,6 +373,22 @@ err:
 }
 
 /*
+ * See if the cached pages should be charged at all?
+ */
+int mem_container_cache_charge(struct page *page, struct mm_struct *mm)
+{
+	struct mem_container *mem;
+	if (!mm)
+		mm = &init_mm;
+
+	mem = rcu_dereference(mm->mem_container);
+	if (mem->control_type == MEM_CONTAINER_TYPE_ALL)
+		return mem_container_charge(page, mm);
+	else
+		return 0;
+}
+
+/*
  * Uncharging is always a welcome operation, we never complain, simply
  * uncharge.
  */
@@ -370,6 +398,10 @@ void mem_container_uncharge(struct page_
 	struct page *page;
 	unsigned long flags;
 
+	/*
+	 * This can handle cases when a page is not charged at all and we
+	 * are switching between handling the control_type.
+	 */
 	if (!pc)
 		return;
 
@@ -405,6 +437,60 @@ static ssize_t mem_container_write(struc
 				cft->private, userbuf, nbytes, ppos);
 }
 
+static ssize_t mem_control_type_write(struct container *cont,
+			struct cftype *cft, struct file *file,
+			const char __user *userbuf,
+			size_t nbytes, loff_t *pos)
+{
+	int ret;
+	char *buf, *end;
+	unsigned long tmp;
+	struct mem_container *mem;
+
+	mem = mem_container_from_cont(cont);
+	buf = kmalloc(nbytes + 1, GFP_KERNEL);
+	ret = -ENOMEM;
+	if (buf == NULL)
+		goto out;
+
+	buf[nbytes] = 0;
+	ret = -EFAULT;
+	if (copy_from_user(buf, userbuf, nbytes))
+		goto out_free;
+
+	ret = -EINVAL;
+	tmp = simple_strtoul(buf, &end, 10);
+	if (*end != '\0')
+		goto out_free;
+
+	if (tmp <= MEM_CONTAINER_TYPE_UNSPEC || tmp >= MEM_CONTAINER_TYPE_MAX)
+		goto out_free;
+
+	mem->control_type = tmp;
+	ret = nbytes;
+out_free:
+	kfree(buf);
+out:
+	return ret;
+}
+
+static ssize_t mem_control_type_read(struct container *cont,
+				struct cftype *cft,
+				struct file *file, char __user *userbuf,
+				size_t nbytes, loff_t *ppos)
+{
+	unsigned long val;
+	char buf[64], *s;
+	struct mem_container *mem;
+
+	mem = mem_container_from_cont(cont);
+	s = buf;
+	val = mem->control_type;
+	s += sprintf(s, "%lu\n", val);
+	return simple_read_from_buffer((void __user *)userbuf, nbytes,
+			ppos, buf, s - buf);
+}
+
 static struct cftype mem_container_files[] = {
 	{
 		.name = "usage",
@@ -422,6 +508,11 @@ static struct cftype mem_container_files
 		.private = RES_FAILCNT,
 		.read = mem_container_read,
 	},
+	{
+		.name = "control_type",
+		.write = mem_control_type_write,
+		.read = mem_control_type_read,
+	},
 };
 
 static struct mem_container init_mem_container;
@@ -444,6 +535,7 @@ mem_container_create(struct container_su
 	INIT_LIST_HEAD(&mem->active_list);
 	INIT_LIST_HEAD(&mem->inactive_list);
 	spin_lock_init(&mem->lru_lock);
+	mem->control_type = MEM_CONTAINER_TYPE_ALL;
 	return &mem->css;
 }
 
diff -puN mm/swap_state.c~mem-control-choose-rss-vs-rss-and-pagecache mm/swap_state.c
--- linux-2.6.23-rc2-mm2/mm/swap_state.c~mem-control-choose-rss-vs-rss-and-pagecache	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/swap_state.c	2007-08-24 20:46:08.000000000 +0530
@@ -82,7 +82,7 @@ static int __add_to_swap_cache(struct pa
 	error = radix_tree_preload(gfp_mask);
 	if (!error) {
 
-		error = mem_container_charge(page, current->mm);
+		error = mem_container_cache_charge(page, current->mm);
 		if (error)
 			goto out;
 
_

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

[-mm PATCH 9/10] Memory controller make page_referenced() container aware (v7)

[Balbir Singh]

Make page_referenced() container aware. Without this patch, page_referenced()
can cause a page to be skipped while reclaiming pages. This patch
ensures that other containers do not hold pages in a particular container
hostage. It is required to ensure that shared pages are freed from a container
when they are not actively referenced from the container that brought
them in


Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

 include/linux/memcontrol.h |    6 ++++++
 include/linux/rmap.h       |    5 +++--
 mm/memcontrol.c            |    5 +++++
 mm/rmap.c                  |   30 ++++++++++++++++++++++++------
 mm/vmscan.c                |    4 ++--
 5 files changed, 40 insertions(+), 10 deletions(-)

diff -puN include/linux/rmap.h~mem-control-per-container-page-referenced include/linux/rmap.h
--- linux-2.6.23-rc2-mm2/include/linux/rmap.h~mem-control-per-container-page-referenced	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/rmap.h	2007-08-24 20:46:08.000000000 +0530
@@ -8,6 +8,7 @@
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/spinlock.h>
+#include <linux/memcontrol.h>
 
 /*
  * The anon_vma heads a list of private "related" vmas, to scan if
@@ -86,7 +87,7 @@ 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 page_referenced(struct page *, int is_locked, struct mem_container *cnt);
 int try_to_unmap(struct page *, int ignore_refs);
 
 /*
@@ -114,7 +115,7 @@ int page_mkclean(struct page *);
 #define anon_vma_prepare(vma)	(0)
 #define anon_vma_link(vma)	do {} while (0)
 
-#define page_referenced(page,l) TestClearPageReferenced(page)
+#define page_referenced(page,l,cnt) TestClearPageReferenced(page)
 #define try_to_unmap(page, refs) SWAP_FAIL
 
 static inline int page_mkclean(struct page *page)
diff -puN mm/rmap.c~mem-control-per-container-page-referenced mm/rmap.c
--- linux-2.6.23-rc2-mm2/mm/rmap.c~mem-control-per-container-page-referenced	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/rmap.c	2007-08-24 20:46:08.000000000 +0530
@@ -299,7 +299,8 @@ out:
 	return referenced;
 }
 
-static int page_referenced_anon(struct page *page)
+static int page_referenced_anon(struct page *page,
+				struct mem_container *mem_cont)
 {
 	unsigned int mapcount;
 	struct anon_vma *anon_vma;
@@ -312,6 +313,13 @@ static int page_referenced_anon(struct p
 
 	mapcount = page_mapcount(page);
 	list_for_each_entry(vma, &anon_vma->head, anon_vma_node) {
+		/*
+		 * If we are reclaiming on behalf of a container, skip
+		 * counting on behalf of references from different
+		 * containers
+		 */
+		if (mem_cont && (mm_container(vma->vm_mm) != mem_cont))
+			continue;
 		referenced += page_referenced_one(page, vma, &mapcount);
 		if (!mapcount)
 			break;
@@ -332,7 +340,8 @@ static int page_referenced_anon(struct p
  *
  * This function is only called from page_referenced for object-based pages.
  */
-static int page_referenced_file(struct page *page)
+static int page_referenced_file(struct page *page,
+				struct mem_container *mem_cont)
 {
 	unsigned int mapcount;
 	struct address_space *mapping = page->mapping;
@@ -365,6 +374,13 @@ static int page_referenced_file(struct p
 	mapcount = page_mapcount(page);
 
 	vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+		/*
+		 * If we are reclaiming on behalf of a container, skip
+		 * counting on behalf of references from different
+		 * containers
+		 */
+		if (mem_cont && (mm_container(vma->vm_mm) != mem_cont))
+			continue;
 		if ((vma->vm_flags & (VM_LOCKED|VM_MAYSHARE))
 				  == (VM_LOCKED|VM_MAYSHARE)) {
 			referenced++;
@@ -387,7 +403,8 @@ static int page_referenced_file(struct p
  * Quick test_and_clear_referenced for all mappings to a page,
  * returns the number of ptes which referenced the page.
  */
-int page_referenced(struct page *page, int is_locked)
+int page_referenced(struct page *page, int is_locked,
+			struct mem_container *mem_cont)
 {
 	int referenced = 0;
 
@@ -399,14 +416,15 @@ int page_referenced(struct page *page, i
 
 	if (page_mapped(page) && page->mapping) {
 		if (PageAnon(page))
-			referenced += page_referenced_anon(page);
+			referenced += page_referenced_anon(page, mem_cont);
 		else if (is_locked)
-			referenced += page_referenced_file(page);
+			referenced += page_referenced_file(page, mem_cont);
 		else if (TestSetPageLocked(page))
 			referenced++;
 		else {
 			if (page->mapping)
-				referenced += page_referenced_file(page);
+				referenced +=
+					page_referenced_file(page, mem_cont);
 			unlock_page(page);
 		}
 	}
diff -puN mm/vmscan.c~mem-control-per-container-page-referenced mm/vmscan.c
--- linux-2.6.23-rc2-mm2/mm/vmscan.c~mem-control-per-container-page-referenced	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/vmscan.c	2007-08-24 20:46:08.000000000 +0530
@@ -511,7 +511,7 @@ static unsigned long shrink_page_list(st
 				goto keep_locked;
 		}
 
-		referenced = page_referenced(page, 1);
+		referenced = page_referenced(page, 1, sc->mem_container);
 		/* In active use or really unfreeable?  Activate it. */
 		if (sc->order <= PAGE_ALLOC_COSTLY_ORDER &&
 					referenced && page_mapping_inuse(page))
@@ -1065,7 +1065,7 @@ force_reclaim_mapped:
 		if (page_mapped(page)) {
 			if (!reclaim_mapped ||
 			    (total_swap_pages == 0 && PageAnon(page)) ||
-			    page_referenced(page, 0)) {
+			    page_referenced(page, 0, sc->mem_container)) {
 				list_add(&page->lru, &l_active);
 				continue;
 			}
diff -puN include/linux/memcontrol.h~mem-control-per-container-page-referenced include/linux/memcontrol.h
--- linux-2.6.23-rc2-mm2/include/linux/memcontrol.h~mem-control-per-container-page-referenced	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/include/linux/memcontrol.h	2007-08-24 20:46:08.000000000 +0530
@@ -43,6 +43,7 @@ extern unsigned long mem_container_isola
 					int active);
 extern void mem_container_out_of_memory(struct mem_container *mem);
 extern int mem_container_cache_charge(struct page *page, struct mm_struct *mm);
+extern struct mem_container *mm_container(struct mm_struct *mm);
 
 static inline void mem_container_uncharge_page(struct page *page)
 {
@@ -93,6 +94,11 @@ static inline int mem_container_cache_ch
 	return 0;
 }
 
+static inline struct mem_container *mm_container(struct mm_struct *mm)
+{
+	return NULL;
+}
+
 #endif /* CONFIG_CONTAINER_MEM_CONT */
 
 #endif /* _LINUX_MEMCONTROL_H */
diff -puN mm/memcontrol.c~mem-control-per-container-page-referenced mm/memcontrol.c
--- linux-2.6.23-rc2-mm2/mm/memcontrol.c~mem-control-per-container-page-referenced	2007-08-24 20:46:08.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/mm/memcontrol.c	2007-08-24 20:46:08.000000000 +0530
@@ -109,6 +109,11 @@ struct mem_container *mem_container_from
 				struct mem_container, css);
 }
 
+inline struct mem_container *mm_container(struct mm_struct *mm)
+{
+	return rcu_dereference(mm->mem_container);
+}
+
 void mm_init_container(struct mm_struct *mm, struct task_struct *p)
 {
 	struct mem_container *mem;
_

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL

[-mm PATCH 10/10] Memory controller add documentation

[Balbir Singh]

Changelog since version 1

1. Wording and punctuation comments - Randy Dunlap
2. Differentiate between RSS and Page Cache - Paul Menage
3. Add detailed description of features - KAMEZAWA Hiroyuki
4. Fix a typo (drop_pages should be drop_caches) - YAMAMOTO Takshi

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

 Documentation/controllers/memory.txt |  259 +++++++++++++++++++++++++++++++++++
 1 file changed, 259 insertions(+)

diff -L Documentation/memcontrol.txt -puN /dev/null /dev/null
diff -puN /dev/null Documentation/controllers/memory.txt
--- /dev/null	2007-06-01 20:42:04.000000000 +0530
+++ linux-2.6.23-rc2-mm2-balbir/Documentation/controllers/memory.txt	2007-08-24 20:46:08.000000000 +0530
@@ -0,0 +1,259 @@
+Memory Controller
+
+Salient features
+
+a. Enable control of both RSS (mapped) and Page Cache (unmapped) pages
+b. The infrastructure allows easy addition of other types of memory to control
+c. Provides *zero overhead* for non memory controller users
+d. Provides a double LRU: global memory pressure causes reclaim from the
+   global LRU; a container on hitting a limit, reclaims from the per
+   container LRU
+
+NOTE: Page Cache (unmapped) also includes Swap Cache pages as a subset
+and will not be referred to explicitly in the rest of the documentation.
+
+Benefits and Purpose of the memory controller
+
+The memory controller isolates the memory behaviour of a group of tasks
+from the rest of the system. The article on LWN [12] mentions some probable
+uses of the memory controller. The memory controller can be used to
+
+a. Isolate an application or a group of applications
+   Memory hungry applications can be isolated and limited to a smaller
+   amount of memory.
+b. Create a container with limited amount of memory, this can be used
+   as a good alternative to booting with mem=XXXX.
+c. Virtualization solutions can control the amount of memory they want
+   to assign to a virtual machine instance.
+d. A CD/DVD burner could control the amount of memory used by the
+   rest of the system to ensure that burning does not fail due to lack
+   of available memory.
+e. There are several other use cases, find one or use the controller just
+   for fun (to learn and hack on the VM subsystem).
+
+1. History
+
+The memory controller has a long history. A request for comments for the memory
+controller was posted by Balbir Singh [1]. At the time the RFC was posted
+there were several implementations for memory control. The goal of the
+RFC was to build consensus and agreement for the minimal features required
+for memory control. The first RSS controller was posted by Balbir Singh[2]
+in Feb 2007. Pavel Emelianov [3][4][5] has since posted three versions of the
+RSS controller. At OLS, at the resource management BoF, everyone suggested
+that we handle both page cache and RSS together. Another request was raised
+to allow user space handling of OOM. The current memory controller is
+at version 6; it combines both mapped (RSS) and unmapped Page
+Cache Control [11].
+
+2. Memory Control
+
+Memory is a unique resource in the sense that it is present in a limited
+amount. If a task requires a lot of CPU processing, the task can spread
+its processing over a period of hours, days, months or years, but with
+memory, the same physical memory needs to be reused to accomplish the task.
+
+The memory controller implementation has been divided into phases. These
+are:
+
+1. Memory controller
+2. mlock(2) controller
+3. Kernel user memory accounting and slab control
+4. user mappings length controller
+
+The memory controller is the first controller developed.
+
+2.1. Design
+
+The core of the design is a counter called the res_counter. The res_counter
+tracks the current memory usage and limit of the group of processes associated
+with the controller. Each container has a memory controller specific data
+structure (mem_container) associated with it.
+
+2.2. Accounting
+
+		+--------------------+
+		|  mem_container     |
+		|  (res_counter)     |
+		+--------------------+
+		 /            ^      \
+		/             |       \
+           +---------------+  |        +---------------+
+           | mm_struct     |  |....    | mm_struct     |
+           |               |  |        |               |
+           +---------------+  |        +---------------+
+                              |
+                              + --------------+
+                                              |
+           +---------------+           +------+--------+
+           | page          +---------->  page_container|
+           |               |           |               |
+           +---------------+           +---------------+
+
+             (Figure 1: Hierarchy of Accounting)
+
+
+Figure 1 shows the important aspects of the controller
+
+1. Accounting happens per container
+2. Each mm_struct knows about which container it belongs to
+3. Each page has a pointer to the page_container, which in turn knows the
+   container it belongs to
+
+The accounting is done as follows: mem_container_charge() is invoked to setup
+the necessary data structures and check if the container that is being charged
+is over its limit. If it is then reclaim is invoked on the container.
+More details can be found in the reclaim section of this document.
+If everything goes well, a page meta-data-structure called page_container is
+allocated and associated with the page.  This routine also adds the page to
+the per container LRU.
+
+2.2.1 Accounting details
+
+All mapped pages (RSS) and unmapped user pages (Page Cache) are accounted.
+RSS pages are accounted at the time of page_add_*_rmap() unless they've already
+been accounted for earlier. A file page will be accounted for as Page Cache;
+it's mapped into the page tables of a process, duplicate accounting is carefully
+avoided. Page Cache pages are accounted at the time of add_to_page_cache().
+The corresponding routines that remove a page from the page tables or removes
+a page from Page Cache is used to decrement the accounting counters of the
+container.
+
+2.3 Shared Page Accounting
+
+Shared pages are accounted on the basis of the first touch approach. The
+container that first touches a page is accounted for the page. The principle
+behind this approach is that a container that aggressively uses a shared
+page will eventually get charged for it (once it is uncharged from
+the container that brought it in -- this will happen on memory pressure).
+
+2.4 Reclaim
+
+Each container maintains a per container LRU that consists of an active
+and inactive list. When a container goes over its limit, we first try
+to reclaim memory from the container so as to make space for the new
+pages that the container has touched. If the reclaim is unsuccessful,
+an OOM routine is invoked to select and kill the bulkiest task in the
+container.
+
+The reclaim algorithm has not been modified for containers, except that
+pages that are selected for reclaiming come from the per container LRU
+list.
+
+2. Locking
+
+The memory controller uses the following hierarchy
+
+1. zone->lru_lock is used for selecting pages to be isolated
+2. mem->lru_lock protects the per container LRU
+3. lock_page_container() is used to protect page->page_container
+
+3. User Interface
+
+0. Configuration
+
+a. Enable CONFIG_CONTAINERS
+b. Enable CONFIG_RESOURCE_COUNTERS
+c. Enable CONFIG_CONTAINER_MEM_CONT
+
+1. Prepare the containers
+# mkdir -p /containers
+# mount -t container none /containers -o memory
+
+2. Make the new group and move bash into it
+# mkdir /containers/0
+# echo $$ >  /containers/0/tasks
+
+Since now we're in the 0 container,
+We can alter the memory limit:
+# echo -n 6000 > /containers/0/memory.limit
+
+We can check the usage:
+# cat /containers/0/memory.usage
+25
+
+The memory.failcnt field gives the number of times that the container limit was
+exceeded.
+
+4. Testing
+
+Balbir posted lmbench, AIM9, LTP and vmmstress results [10] and [11].
+Apart from that v6 has been tested with several applications and regular
+daily use. The controller has also been tested on the PPC64, x86_64 and
+UML platforms.
+
+4.1 Troubleshooting
+
+Sometimes a user might find that the application under a container is
+terminated. There are several causes for this:
+
+1. The container limit is too low (just too low to do anything useful)
+2. The user is using anonymous memory and swap is turned off or too low
+
+A sync followed by echo 1 > /proc/sys/vm/drop_caches will help get rid of
+some of the pages cached in the container (page cache pages).
+
+4.2 Task migration
+
+When a task migrates from one container to another, it's charge is not
+carried forward. The pages allocated from the original container still
+remain charged to it, the charge is dropped when the page is freed or
+reclaimed.
+
+4.3 Removing a container
+
+A container can be removed by rmdir, but as discussed in sections 4.1 and 4.2, a
+container might have some charge associated with it, even though all
+tasks have migrated away from it. If some pages are still left, after following
+the steps listed in sections 4.1 and 4.2, check the Swap Cache usage in
+/proc/meminfo to see if the Swap Cache usage is showing up in the
+containers memory.usage counter. A simple test of swapoff -a and swapon -a
+should free any pending Swap Cache usage.
+
+4.4 Choosing what to account  -- Page Cache (unmapped) vs RSS (mapped)?
+
+The type of memory accounted by the container can be limited to just
+mapped pages by writing "1" to memory.control_type field
+
+echo -n 1 > memory.control_type
+
+5. TODO
+
+1. Add support for accounting huge pages (as a separate controller)
+2. Improve the user interface to accept/display memory limits in KB or MB
+   rather than pages (since page sizes can differ across platforms/machines).
+3. Make container lists per-zone
+4. Make per-container scanner reclaim not-shared pages first
+5. Teach controller to account for shared-pages
+6. Start reclamation when the limit is lowered
+7. Start reclamation in the background when the limit is
+   not yet hit but the usage is getting closer
+8. Create per zone LRU lists per container
+
+Summary
+
+Overall, the memory controller has been a stable controller and has been
+commented and discussed quite extensively in the community.
+
+References
+
+1. Singh, Balbir. RFC: Memory Controller, http://lwn.net/Articles/206697/
+2. Singh, Balbir. Memory Controller (RSS Control),
+   http://lwn.net/Articles/222762/
+3. Emelianov, Pavel. Resource controllers based on process containers
+   http://lkml.org/lkml/2007/3/6/198
+4. Emelianov, Pavel. RSS controller based on process containers (v2)
+   http://lkml.org/lkml/2007/4/9/74
+5. Emelianov, Pavel. RSS controller based on process containers (v3)
+   http://lkml.org/lkml/2007/5/30/244
+6. Menage, Paul. Containers v10, http://lwn.net/Articles/236032/
+7. Vaidyanathan, Srinivasan, Containers: Pagecache accounting and control
+   subsystem (v3), http://lwn.net/Articles/235534/
+8. Singh, Balbir. RSS controller V2 test results (lmbench),
+   http://lkml.org/lkml/2007/5/17/232
+9. Singh, Balbir. RSS controller V2 AIM9 results
+   http://lkml.org/lkml/2007/5/18/1
+10. Singh, Balbir. Memory controller v6 results,
+    http://lkml.org/lkml/2007/8/19/36
+11. Singh, Balbir. Memory controller v6, http://lkml.org/lkml/2007/8/17/69
+12. Corbet, Jonathan, Controlling memory use in containers,
+    http://lwn.net/Articles/243795/
_

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL