3 * Copyright IBM Corporation, 2012
4 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of version 2.1 of the GNU Lesser General Public License
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it would be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
16 #include <linux/cgroup.h>
17 #include <linux/slab.h>
18 #include <linux/hugetlb.h>
19 #include <linux/hugetlb_cgroup.h>
21 struct hugetlb_cgroup {
22 struct cgroup_subsys_state css;
24 * the counter to account for hugepages from hugetlb.
26 struct res_counter hugepage[HUGE_MAX_HSTATE];
29 struct cgroup_subsys hugetlb_subsys __read_mostly;
30 static struct hugetlb_cgroup *root_h_cgroup __read_mostly;
33 struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s)
35 return container_of(s, struct hugetlb_cgroup, css);
39 struct hugetlb_cgroup *hugetlb_cgroup_from_cgroup(struct cgroup *cgroup)
41 return hugetlb_cgroup_from_css(cgroup_subsys_state(cgroup,
46 struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task)
48 return hugetlb_cgroup_from_css(task_subsys_state(task,
52 static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg)
54 return (h_cg == root_h_cgroup);
57 static inline struct hugetlb_cgroup *parent_hugetlb_cgroup(struct cgroup *cg)
61 return hugetlb_cgroup_from_cgroup(cg->parent);
64 static inline bool hugetlb_cgroup_have_usage(struct cgroup *cg)
67 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cg);
69 for (idx = 0; idx < hugetlb_max_hstate; idx++) {
70 if ((res_counter_read_u64(&h_cg->hugepage[idx], RES_USAGE)) > 0)
76 static struct cgroup_subsys_state *hugetlb_cgroup_create(struct cgroup *cgroup)
79 struct cgroup *parent_cgroup;
80 struct hugetlb_cgroup *h_cgroup, *parent_h_cgroup;
82 h_cgroup = kzalloc(sizeof(*h_cgroup), GFP_KERNEL);
84 return ERR_PTR(-ENOMEM);
86 parent_cgroup = cgroup->parent;
88 parent_h_cgroup = hugetlb_cgroup_from_cgroup(parent_cgroup);
89 for (idx = 0; idx < HUGE_MAX_HSTATE; idx++)
90 res_counter_init(&h_cgroup->hugepage[idx],
91 &parent_h_cgroup->hugepage[idx]);
93 root_h_cgroup = h_cgroup;
94 for (idx = 0; idx < HUGE_MAX_HSTATE; idx++)
95 res_counter_init(&h_cgroup->hugepage[idx], NULL);
97 return &h_cgroup->css;
100 static void hugetlb_cgroup_destroy(struct cgroup *cgroup)
102 struct hugetlb_cgroup *h_cgroup;
104 h_cgroup = hugetlb_cgroup_from_cgroup(cgroup);
108 static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup)
110 /* We will add the cgroup removal support in later patches */
114 struct cgroup_subsys hugetlb_subsys = {
116 .create = hugetlb_cgroup_create,
117 .pre_destroy = hugetlb_cgroup_pre_destroy,
118 .destroy = hugetlb_cgroup_destroy,
119 .subsys_id = hugetlb_subsys_id,