root/include/linux/hugetlb_cgroup.h

DEFINITIONS

1. hugetlb_cgroup_from_page
2. set_hugetlb_cgroup
3. hugetlb_cgroup_disabled
4. hugetlb_cgroup_file_init
5. set_hugetlb_cgroup
6. hugetlb_cgroup_disabled
7. hugetlb_cgroup_charge_cgroup
8. hugetlb_cgroup_commit_charge
9. hugetlb_cgroup_uncharge_page
10. hugetlb_cgroup_uncharge_cgroup
11. hugetlb_cgroup_file_init
12. hugetlb_cgroup_migrate

/*
 * 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/mmdebug.h>
#include <linux/res_counter.h>

struct hugetlb_cgroup;
/*
 * Minimum page order trackable by hugetlb cgroup.
 * At least 3 pages are necessary for all the tracking information.
 */
#define HUGETLB_CGROUP_MIN_ORDER        2

#ifdef CONFIG_CGROUP_HUGETLB

static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
{
        VM_BUG_ON_PAGE(!PageHuge(page), page);

        if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
                return NULL;
        return (struct hugetlb_cgroup *)page[2].lru.next;
}

static inline
int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)
{
        VM_BUG_ON_PAGE(!PageHuge(page), page);

        if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
                return -1;
        page[2].lru.next = (void *)h_cg;
        return 0;
}

static inline bool hugetlb_cgroup_disabled(void)
{
        if (hugetlb_cgrp_subsys.disabled)
                return true;
        return false;
}

extern int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
                                        struct hugetlb_cgroup **ptr);
extern void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
                                         struct hugetlb_cgroup *h_cg,
                                         struct page *page);
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 void hugetlb_cgroup_file_init(void) __init;
extern void hugetlb_cgroup_migrate(struct page *oldhpage,
                                   struct page *newhpage);

#else
static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
{
        return NULL;
}

static inline
int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)
{
        return 0;
}

static inline bool hugetlb_cgroup_disabled(void)
{
        return true;
}

static inline int
hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
                             struct hugetlb_cgroup **ptr)
{
        return 0;
}

static inline void
hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
                             struct hugetlb_cgroup *h_cg,
                             struct page *page)
{
        return;
}

static inline void
hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, struct page *page)
{
        return;
}

static inline void
hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
                               struct hugetlb_cgroup *h_cg)
{
        return;
}

static inline void hugetlb_cgroup_file_init(void)
{
}

static inline void hugetlb_cgroup_migrate(struct page *oldhpage,
                                          struct page *newhpage)
{
        return;
}

#endif  /* CONFIG_MEM_RES_CTLR_HUGETLB */
#endif