memcg: limit change shrink usage
Shrinking memory usage at limit change.
[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0c03564..fba566c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -812,6 +812,30 @@
return 0;
}
+int mem_cgroup_resize_limit(struct mem_cgroup *memcg, unsigned long long val)
+{
+
+ int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
+ int progress;
+ int ret = 0;
+
+ while (res_counter_set_limit(&memcg->res, val)) {
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+ if (!retry_count) {
+ ret = -EBUSY;
+ break;
+ }
+ progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL);
+ if (!progress)
+ retry_count--;
+ }
+ return ret;
+}
+
+
/*
* This routine traverse page_cgroup in given list and drop them all.
* *And* this routine doesn't reclaim page itself, just removes page_cgroup.
@@ -896,13 +920,29 @@
return res_counter_read_u64(&mem_cgroup_from_cont(cont)->res,
cft->private);
}
-
+/*
+ * The user of this function is...
+ * RES_LIMIT.
+ */
static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
const char *buffer)
{
- return res_counter_write(&mem_cgroup_from_cont(cont)->res,
- cft->private, buffer,
- res_counter_memparse_write_strategy);
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ unsigned long long val;
+ int ret;
+
+ switch (cft->private) {
+ case RES_LIMIT:
+ /* This function does all necessary parse...reuse it */
+ ret = res_counter_memparse_write_strategy(buffer, &val);
+ if (!ret)
+ ret = mem_cgroup_resize_limit(memcg, val);
+ break;
+ default:
+ ret = -EINVAL; /* should be BUG() ? */
+ break;
+ }
+ return ret;
}
static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)