2 * Macros for manipulating and testing flags related to a
3 * pageblock_nr_pages number of pages.
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
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.
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.
18 * Copyright (C) IBM Corporation, 2006
20 * Original author, Mel Gorman
21 * Major cleanups and reduction of bit operations, Andy Whitcroft
23 #ifndef PAGEBLOCK_FLAGS_H
24 #define PAGEBLOCK_FLAGS_H
26 #include <linux/types.h>
28 /* Bit indices that affect a whole block of pages */
31 PB_migrate_end
= PB_migrate
+ 3 - 1,
32 /* 3 bits required for migrate types */
33 PB_migrate_skip
,/* If set the block is skipped by compaction */
36 * Assume the bits will always align on a word. If this assumption
37 * changes then get/set pageblock needs updating.
42 #ifdef CONFIG_HUGETLB_PAGE
44 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
46 /* Huge page sizes are variable */
47 extern int pageblock_order
;
49 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
51 /* Huge pages are a constant size */
52 #define pageblock_order HUGETLB_PAGE_ORDER
54 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
56 #else /* CONFIG_HUGETLB_PAGE */
58 /* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
59 #define pageblock_order (MAX_ORDER-1)
61 #endif /* CONFIG_HUGETLB_PAGE */
63 #define pageblock_nr_pages (1UL << pageblock_order)
65 /* Forward declaration */
68 unsigned long get_pfnblock_flags_mask(struct page
*page
,
70 unsigned long end_bitidx
,
73 void set_pfnblock_flags_mask(struct page
*page
,
76 unsigned long end_bitidx
,
79 /* Declarations for getting and setting flags. See mm/page_alloc.c */
80 #define get_pageblock_flags_group(page, start_bitidx, end_bitidx) \
81 get_pfnblock_flags_mask(page, page_to_pfn(page), \
83 (1 << (end_bitidx - start_bitidx + 1)) - 1)
84 #define set_pageblock_flags_group(page, flags, start_bitidx, end_bitidx) \
85 set_pfnblock_flags_mask(page, flags, page_to_pfn(page), \
87 (1 << (end_bitidx - start_bitidx + 1)) - 1)
89 #ifdef CONFIG_COMPACTION
90 #define get_pageblock_skip(page) \
91 get_pageblock_flags_group(page, PB_migrate_skip, \
93 #define clear_pageblock_skip(page) \
94 set_pageblock_flags_group(page, 0, PB_migrate_skip, \
96 #define set_pageblock_skip(page) \
97 set_pageblock_flags_group(page, 1, PB_migrate_skip, \
99 #endif /* CONFIG_COMPACTION */
101 #endif /* PAGEBLOCK_FLAGS_H */
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