Kamezawa Hiroyuki [off-list ref] writes:

(2012/06/09 17:59), Aneesh Kumar K.V wrote:

quoted

From: "Aneesh Kumar K.V"<redacted>

Add the control files for hugetlb controller

Signed-off-by: Aneesh Kumar K.V<redacted>
---
  include/linux/hugetlb.h        |    5 ++
  include/linux/hugetlb_cgroup.h |    6 ++
  mm/hugetlb.c                   |    8 +++
  mm/hugetlb_cgroup.c            |  130 ++++++++++++++++++++++++++++++++++++++++
  4 files changed, 149 insertions(+)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 4aca057..9650bb1 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h

@@ -4,6 +4,7 @@
  #include<linux/mm_types.h>
  #include<linux/fs.h>
  #include<linux/hugetlb_inline.h>
+#include<linux/cgroup.h>

  struct ctl_table;
  struct user_struct;

@@ -221,6 +222,10 @@ struct hstate {
  	unsigned int nr_huge_pages_node[MAX_NUMNODES];
  	unsigned int free_huge_pages_node[MAX_NUMNODES];
  	unsigned int surplus_huge_pages_node[MAX_NUMNODES];
+#ifdef CONFIG_CGROUP_HUGETLB_RES_CTLR
+	/* cgroup control files */
+	struct cftype cgroup_files[5];
+#endif
  	char name[HSTATE_NAME_LEN];
  };

diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h
index ceff1d5..ba4836f 100644
--- a/include/linux/hugetlb_cgroup.h
+++ b/include/linux/hugetlb_cgroup.h

@@ -62,6 +62,7 @@ extern void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,
  					 struct page *page);
  extern void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
  					   struct hugetlb_cgroup *h_cg);
+extern int hugetlb_cgroup_file_init(int idx) __init;
  #else
  static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
  {

@@ -106,5 +107,10 @@ hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
  {
  	return;
  }
+
+static inline int __init hugetlb_cgroup_file_init(int idx)
+{
+	return 0;
+}
  #endif  /* CONFIG_MEM_RES_CTLR_HUGETLB */
  #endif

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 1ca2d8f..bf79131 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c

@@ -30,6 +30,7 @@
  #include<linux/hugetlb.h>
  #include<linux/hugetlb_cgroup.h>
  #include<linux/node.h>
+#include<linux/hugetlb_cgroup.h>
  #include "internal.h"

  const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;

@@ -1916,6 +1917,13 @@ void __init hugetlb_add_hstate(unsigned order)
  	h->next_nid_to_free = first_node(node_states[N_HIGH_MEMORY]);
  	snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
  					huge_page_size(h)/1024);
+	/*
+	 * Add cgroup control files only if the huge page consists
+	 * of more than two normal pages. This is because we use
+	 * page[2].lru.next for storing cgoup details.
+	 */
+	if (order>= 2)
+		hugetlb_cgroup_file_init(hugetlb_max_hstate - 1);

What happens at hugetlb module exit ? please see hugetlb_exit().

BTW, module unload of hugetlbfs is restricted if hugetlb cgroup is mounted ??

hugetlb is a binary config

config HUGETLBFS
	bool "HugeTLB file system support"

config HUGETLB_PAGE
	def_bool HUGETLBFS

-aneesh