memcg: add interface to reset limits
We don't have an interface to reset mem.limit or memsw.limit now.
This patch allows to reset mem.limit or memsw.limit when they are being
set to -1.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index af48135..23d1262 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -209,6 +209,7 @@
NOTE: We can use a suffix (k, K, m, M, g or G) to indicate values in kilo,
mega or gigabytes.
+NOTE: We can write "-1" to reset the *.limit_in_bytes(unlimited).
# cat /cgroups/0/memory.limit_in_bytes
4194304
diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h
index 4c5bcf6..511f42f 100644
--- a/include/linux/res_counter.h
+++ b/include/linux/res_counter.h
@@ -49,6 +49,8 @@
struct res_counter *parent;
};
+#define RESOURCE_MAX (unsigned long long)LLONG_MAX
+
/**
* Helpers to interact with userspace
* res_counter_read_u64() - returns the value of the specified member.
diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index bf8e753..e1338f0 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -18,7 +18,7 @@
void res_counter_init(struct res_counter *counter, struct res_counter *parent)
{
spin_lock_init(&counter->lock);
- counter->limit = (unsigned long long)LLONG_MAX;
+ counter->limit = RESOURCE_MAX;
counter->parent = parent;
}
@@ -133,6 +133,16 @@
unsigned long long *res)
{
char *end;
+
+ /* return RESOURCE_MAX(unlimited) if "-1" is specified */
+ if (*buf == '-') {
+ *res = simple_strtoull(buf + 1, &end, 10);
+ if (*res != 1 || *end != '\0')
+ return -EINVAL;
+ *res = RESOURCE_MAX;
+ return 0;
+ }
+
/* FIXME - make memparse() take const char* args */
*res = memparse((char *)buf, &end);
if (*end != '\0')