Memory Resource Controller use strstrip while parsing arguments

The memory controller has a requirement that while writing values, we need
to use echo -n. This patch fixes the problem and makes the UI more consistent.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/controllers/memory.txt

@@ -164,7 +164,7 @@ c. Enable CONFIG_CGROUP_MEM_CONT
 
 Since now we're in the 0 cgroup,
 We can alter the memory limit:
-# echo -n 4M > /cgroups/0/memory.limit_in_bytes
+# echo 4M > /cgroups/0/memory.limit_in_bytes
 
 NOTE: We can use a suffix (k, K, m, M, g or G) to indicate values in kilo,
 mega or gigabytes.
@@ -185,7 +185,7 @@ number of factors, such as rounding up to page boundaries or the total
 availability of memory on the system.  The user is required to re-read
 this file after a write to guarantee the value committed by the kernel.
 
-# echo -n 1 > memory.limit_in_bytes
+# echo 1 > memory.limit_in_bytes
 # cat memory.limit_in_bytes
 4096
 
@@ -197,7 +197,7 @@ caches, RSS and Active pages/Inactive pages are shown.
 
 The memory.force_empty gives an interface to drop *all* charges by force.
 
-# echo -n 1 > memory.force_empty
+# echo 1 > memory.force_empty
 
 will drop all charges in cgroup. Currently, this is maintained for test.
 

kernel/res_counter.c

@@ -113,6 +113,7 @@ ssize_t res_counter_write(struct res_counter *counter, int member,
 
 	ret = -EINVAL;
 
+	strstrip(buf);
 	if (write_strategy) {
 		if (write_strategy(buf, &tmp)) {
 			goto out_free;