Memory controller improve user interface
Change the interface to use bytes instead of pages. Page sizes can vary
across platforms and configurations. A new strategy routine has been added
to the resource counters infrastructure to format the data as desired.
Suggested by David Rientjes, Andrew Morton and Herbert Poetzl
Tested on a UML setup with the config for memory control enabled.
[kamezawa.hiroyu@jp.fujitsu.com: possible race fix in res_counter]
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9e9ff91..d736922 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -302,7 +302,7 @@
* If we created the page_cgroup, we should free it on exceeding
* the cgroup limit.
*/
- while (res_counter_charge(&mem->res, 1)) {
+ while (res_counter_charge(&mem->res, PAGE_SIZE)) {
if (try_to_free_mem_cgroup_pages(mem))
continue;
@@ -341,7 +341,7 @@
kfree(pc);
pc = race_pc;
atomic_inc(&pc->ref_cnt);
- res_counter_uncharge(&mem->res, 1);
+ res_counter_uncharge(&mem->res, PAGE_SIZE);
css_put(&mem->css);
goto done;
}
@@ -384,7 +384,7 @@
css_put(&mem->css);
page_assign_page_cgroup(page, NULL);
unlock_page_cgroup(page);
- res_counter_uncharge(&mem->res, 1);
+ res_counter_uncharge(&mem->res, PAGE_SIZE);
spin_lock_irqsave(&mem->lru_lock, flags);
list_del_init(&pc->lru);
@@ -393,12 +393,26 @@
}
}
-static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft,
- struct file *file, char __user *userbuf, size_t nbytes,
- loff_t *ppos)
+int mem_cgroup_write_strategy(char *buf, unsigned long long *tmp)
+{
+ *tmp = memparse(buf, &buf);
+ if (*buf != '\0')
+ return -EINVAL;
+
+ /*
+ * Round up the value to the closest page size
+ */
+ *tmp = ((*tmp + PAGE_SIZE - 1) >> PAGE_SHIFT) << PAGE_SHIFT;
+ return 0;
+}
+
+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);
+ cft->private, userbuf, nbytes, ppos,
+ NULL);
}
static ssize_t mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
@@ -406,17 +420,18 @@
size_t nbytes, loff_t *ppos)
{
return res_counter_write(&mem_cgroup_from_cont(cont)->res,
- cft->private, userbuf, nbytes, ppos);
+ cft->private, userbuf, nbytes, ppos,
+ mem_cgroup_write_strategy);
}
static struct cftype mem_cgroup_files[] = {
{
- .name = "usage",
+ .name = "usage_in_bytes",
.private = RES_USAGE,
.read = mem_cgroup_read,
},
{
- .name = "limit",
+ .name = "limit_in_bytes",
.private = RES_LIMIT,
.write = mem_cgroup_write,
.read = mem_cgroup_read,