mm/hugetlb: add new HugeTLB cgroup

Implement a new controller that allows us to control HugeTLB allocations.
The extension allows to limit the HugeTLB usage per control group and
enforces the controller limit during page fault.  Since HugeTLB doesn't
support page reclaim, enforcing the limit at page fault time implies that,
the application will get SIGBUS signal if it tries to access HugeTLB pages
beyond its limit.  This requires the application to know beforehand how
much HugeTLB pages it would require for its use.

The charge/uncharge calls will be added to HugeTLB code in later patch.
Support for cgroup removal will be added in later patches.

[akpm@linux-foundation.org: s/CONFIG_CGROUP_HUGETLB_RES_CTLR/CONFIG_MEMCG_HUGETLB/g]
[akpm@linux-foundation.org: s/CONFIG_MEMCG_HUGETLB/CONFIG_CGROUP_HUGETLB/g]
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 43 insertions, 0 deletions

diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index 0bd390ce98b2..5b41ce079024 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -72,3 +72,9 @@ SUBSYS(net_prio)
 #endif
 
 /* */
+
+#ifdef CONFIG_CGROUP_HUGETLB
+SUBSYS(hugetlb)
+#endif
+
+/* */
diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h
new file mode 100644
index 000000000000..f19889e56b47
--- /dev/null
+++ b/include/linux/hugetlb_cgroup.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright IBM Corporation, 2012
+ * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#ifndef _LINUX_HUGETLB_CGROUP_H
+#define _LINUX_HUGETLB_CGROUP_H
+
+#include <linux/res_counter.h>
+
+struct hugetlb_cgroup;
+
+#ifdef CONFIG_CGROUP_HUGETLB
+static inline bool hugetlb_cgroup_disabled(void)
+{
+	if (hugetlb_subsys.disabled)
+		return true;
+	return false;
+}
+
+#else
+static inline bool hugetlb_cgroup_disabled(void)
+{
+	return true;
+}
+
+#endif  /* CONFIG_MEM_RES_CTLR_HUGETLB */
+#endif