/* 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/cgroup.h>
struct cgroup_subsys mem_cgroup_subsys;
/*
* The memory controller data structure. The memory controller controls both
* page cache and RSS per cgroup. 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_cgroup {
struct cgroup_subsys_state css;
/*
* the counter to account for memory usage
*/
struct res_counter res;
};
/*
* A page_cgroup page is associated with every page descriptor. The
* page_cgroup helps us identify information about the cgroup
*/
struct page_cgroup {
struct list_head lru; /* per cgroup LRU list */
struct page *page;
struct mem_cgroup *mem_cgroup;
};
static inline
struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
{
return container_of(cgroup_subsys_state(cont,
mem_cgroup_subsys_id), struct mem_cgroup,
css);
}
static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft,
struct file *file, char __user *userbuf, size_t nbytes,
loff_t *ppos)
{
return res_counter_read(&mem_cgroup_from_cont(cont)->res,
cft->private, userbuf, nbytes, ppos);
}
static ssize_t mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
struct file *file, const char __user *userbuf,
size_t nbytes, loff_t *ppos)
{
return res_counter_write(&mem_cgroup_from_cont(cont)->res,
cft->private, userbuf, nbytes, ppos);
}
static struct cftype mem_cgroup_files[] = {
{
.name = "usage",
.private = RES_USAGE,
.read = mem_cgroup_read,
},
{
.name = "limit",
.private = RES_LIMIT,
.write = mem_cgroup_write,
.read = mem_cgroup_read,
},
{
.name = "failcnt",
.private = RES_FAILCNT,
.read = mem_cgroup_read,
},
};
static struct cgroup_subsys_state *
mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
{
struct mem_cgroup *mem;
mem = kzalloc(sizeof(struct mem_cgroup), GFP_KERNEL);
if (!mem)
return -ENOMEM;
res_counter_init(&mem->res);
return &mem->css;
}
static void mem_cgroup_destroy(struct cgroup_subsys *ss,
struct cgroup *cont)
{
kfree(mem_cgroup_from_cont(cont));
}
static int mem_cgroup_populate(struct cgroup_subsys *ss,
struct cgroup *cont)
{
return cgroup_add_files(cont, ss, mem_cgroup_files,
ARRAY_SIZE(mem_cgroup_files));
}
struct cgroup_subsys mem_cgroup_subsys = {
.name = "memory",
.subsys_id = mem_cgroup_subsys_id,
.create = mem_cgroup_create,
.destroy = mem_cgroup_destroy,
.populate = mem_cgroup_populate,
.early_init = 0,
};
