memcontrol.c revision 78fb74669e80883323391090e4d26d17fe29488f 
1/* memcontrol.c - Memory Controller
2 *
3 * Copyright IBM Corporation, 2007
4 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
5 *
6 * Copyright 2007 OpenVZ SWsoft Inc
7 * Author: Pavel Emelianov <xemul@openvz.org>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 */
19
20#include <linux/res_counter.h>
21#include <linux/memcontrol.h>
22#include <linux/cgroup.h>
23#include <linux/mm.h>
24
25struct cgroup_subsys mem_cgroup_subsys;
26
27/*
28 * The memory controller data structure. The memory controller controls both
29 * page cache and RSS per cgroup. We would eventually like to provide
30 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
31 * to help the administrator determine what knobs to tune.
32 *
33 * TODO: Add a water mark for the memory controller. Reclaim will begin when
34 * we hit the water mark.
35 */
36struct mem_cgroup {
37	struct cgroup_subsys_state css;
38	/*
39	 * the counter to account for memory usage
40	 */
41	struct res_counter res;
42	/*
43	 * Per cgroup active and inactive list, similar to the
44	 * per zone LRU lists.
45	 * TODO: Consider making these lists per zone
46	 */
47	struct list_head active_list;
48	struct list_head inactive_list;
49};
50
51/*
52 * A page_cgroup page is associated with every page descriptor. The
53 * page_cgroup helps us identify information about the cgroup
54 */
55struct page_cgroup {
56	struct list_head lru;		/* per cgroup LRU list */
57	struct page *page;
58	struct mem_cgroup *mem_cgroup;
59};
60
61
62static inline
63struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
64{
65	return container_of(cgroup_subsys_state(cont,
66				mem_cgroup_subsys_id), struct mem_cgroup,
67				css);
68}
69
70static inline
71struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
72{
73	return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
74				struct mem_cgroup, css);
75}
76
77void mm_init_cgroup(struct mm_struct *mm, struct task_struct *p)
78{
79	struct mem_cgroup *mem;
80
81	mem = mem_cgroup_from_task(p);
82	css_get(&mem->css);
83	mm->mem_cgroup = mem;
84}
85
86void mm_free_cgroup(struct mm_struct *mm)
87{
88	css_put(&mm->mem_cgroup->css);
89}
90
91void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc)
92{
93	page->page_cgroup = (unsigned long)pc;
94}
95
96struct page_cgroup *page_get_page_cgroup(struct page *page)
97{
98	return page->page_cgroup;
99}
100
101static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft,
102			struct file *file, char __user *userbuf, size_t nbytes,
103			loff_t *ppos)
104{
105	return res_counter_read(&mem_cgroup_from_cont(cont)->res,
106				cft->private, userbuf, nbytes, ppos);
107}
108
109static ssize_t mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
110				struct file *file, const char __user *userbuf,
111				size_t nbytes, loff_t *ppos)
112{
113	return res_counter_write(&mem_cgroup_from_cont(cont)->res,
114				cft->private, userbuf, nbytes, ppos);
115}
116
117static struct cftype mem_cgroup_files[] = {
118	{
119		.name = "usage",
120		.private = RES_USAGE,
121		.read = mem_cgroup_read,
122	},
123	{
124		.name = "limit",
125		.private = RES_LIMIT,
126		.write = mem_cgroup_write,
127		.read = mem_cgroup_read,
128	},
129	{
130		.name = "failcnt",
131		.private = RES_FAILCNT,
132		.read = mem_cgroup_read,
133	},
134};
135
136static struct mem_cgroup init_mem_cgroup;
137
138static struct cgroup_subsys_state *
139mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
140{
141	struct mem_cgroup *mem;
142
143	if (unlikely((cont->parent) == NULL)) {
144		mem = &init_mem_cgroup;
145		init_mm.mem_cgroup = mem;
146	} else
147		mem = kzalloc(sizeof(struct mem_cgroup), GFP_KERNEL);
148
149	if (mem == NULL)
150		return NULL;
151
152	res_counter_init(&mem->res);
153	return &mem->css;
154}
155
156static void mem_cgroup_destroy(struct cgroup_subsys *ss,
157				struct cgroup *cont)
158{
159	kfree(mem_cgroup_from_cont(cont));
160}
161
162static int mem_cgroup_populate(struct cgroup_subsys *ss,
163				struct cgroup *cont)
164{
165	return cgroup_add_files(cont, ss, mem_cgroup_files,
166					ARRAY_SIZE(mem_cgroup_files));
167}
168
169struct cgroup_subsys mem_cgroup_subsys = {
170	.name = "memory",
171	.subsys_id = mem_cgroup_subsys_id,
172	.create = mem_cgroup_create,
173	.destroy = mem_cgroup_destroy,
174	.populate = mem_cgroup_populate,
175	.early_init = 1,
176};
177