Linux kernel mirror (for testing)
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1/*
2 * Macros for manipulating and testing flags related to a
3 * pageblock_nr_pages number of pages.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation version 2 of the License
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Copyright (C) IBM Corporation, 2006
19 *
20 * Original author, Mel Gorman
21 * Major cleanups and reduction of bit operations, Andy Whitcroft
22 */
23#ifndef PAGEBLOCK_FLAGS_H
24#define PAGEBLOCK_FLAGS_H
25
26#include <linux/types.h>
27
28/* Bit indices that affect a whole block of pages */
29enum pageblock_bits {
30 PB_migrate,
31 PB_migrate_end = PB_migrate + 3 - 1,
32 /* 3 bits required for migrate types */
33#ifdef CONFIG_COMPACTION
34 PB_migrate_skip,/* If set the block is skipped by compaction */
35#endif /* CONFIG_COMPACTION */
36 NR_PAGEBLOCK_BITS
37};
38
39#ifdef CONFIG_HUGETLB_PAGE
40
41#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
42
43/* Huge page sizes are variable */
44extern int pageblock_order;
45
46#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
47
48/* Huge pages are a constant size */
49#define pageblock_order HUGETLB_PAGE_ORDER
50
51#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
52
53#else /* CONFIG_HUGETLB_PAGE */
54
55/* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
56#define pageblock_order (MAX_ORDER-1)
57
58#endif /* CONFIG_HUGETLB_PAGE */
59
60#define pageblock_nr_pages (1UL << pageblock_order)
61
62/* Forward declaration */
63struct page;
64
65/* Declarations for getting and setting flags. See mm/page_alloc.c */
66unsigned long get_pageblock_flags_group(struct page *page,
67 int start_bitidx, int end_bitidx);
68void set_pageblock_flags_group(struct page *page, unsigned long flags,
69 int start_bitidx, int end_bitidx);
70
71#ifdef CONFIG_COMPACTION
72#define get_pageblock_skip(page) \
73 get_pageblock_flags_group(page, PB_migrate_skip, \
74 PB_migrate_skip)
75#define clear_pageblock_skip(page) \
76 set_pageblock_flags_group(page, 0, PB_migrate_skip, \
77 PB_migrate_skip)
78#define set_pageblock_skip(page) \
79 set_pageblock_flags_group(page, 1, PB_migrate_skip, \
80 PB_migrate_skip)
81#endif /* CONFIG_COMPACTION */
82
83#endif /* PAGEBLOCK_FLAGS_H */