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 #define PB_migratetype_bits 3
29 /* Bit indices that affect a whole block of pages */
32 PB_migrate_end = PB_migrate + PB_migratetype_bits - 1,
33 /* 3 bits required for migrate types */
34 PB_migrate_skip,/* If set the block is skipped by compaction */
37 * Assume the bits will always align on a word. If this assumption
38 * changes then get/set pageblock needs updating.
43 #ifdef CONFIG_HUGETLB_PAGE
45 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
47 /* Huge page sizes are variable */
48 extern unsigned int pageblock_order;
50 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
52 /* Huge pages are a constant size */
53 #define pageblock_order HUGETLB_PAGE_ORDER
55 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
57 #else /* CONFIG_HUGETLB_PAGE */
59 /* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
60 #define pageblock_order (MAX_ORDER-1)
62 #endif /* CONFIG_HUGETLB_PAGE */
64 #define pageblock_nr_pages (1UL << pageblock_order)
66 /* Forward declaration */
69 unsigned long get_pfnblock_flags_mask(struct page *page,
71 unsigned long end_bitidx,
74 void set_pfnblock_flags_mask(struct page *page,
77 unsigned long end_bitidx,
80 /* Declarations for getting and setting flags. See mm/page_alloc.c */
81 #define get_pageblock_flags_group(page, start_bitidx, end_bitidx) \
82 get_pfnblock_flags_mask(page, page_to_pfn(page), \
84 (1 << (end_bitidx - start_bitidx + 1)) - 1)
85 #define set_pageblock_flags_group(page, flags, start_bitidx, end_bitidx) \
86 set_pfnblock_flags_mask(page, flags, page_to_pfn(page), \
88 (1 << (end_bitidx - start_bitidx + 1)) - 1)
90 #ifdef CONFIG_COMPACTION
91 #define get_pageblock_skip(page) \
92 get_pageblock_flags_group(page, PB_migrate_skip, \
94 #define clear_pageblock_skip(page) \
95 set_pageblock_flags_group(page, 0, PB_migrate_skip, \
97 #define set_pageblock_skip(page) \
98 set_pageblock_flags_group(page, 1, PB_migrate_skip, \
101 static inline bool get_pageblock_skip(struct page *page)
105 static inline void clear_pageblock_skip(struct page *page)
108 static inline void set_pageblock_skip(struct page *page)
111 #endif /* CONFIG_COMPACTION */
113 #endif /* PAGEBLOCK_FLAGS_H */