1 files changed, 127 insertions, 0 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
new file mode 100644
index 000000000000..80e48cd9d0c7
--- /dev/null
+++ b/mm/memcontrol.c
@@ -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/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,
+};