/* * Macros for manipulating and testing flags related to a * pageblock_nr_pages number of pages. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation version 2 of the License * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Copyright (C) IBM Corporation, 2006 * * Original author, Mel Gorman * Major cleanups and reduction of bit operations, Andy Whitcroft */ #ifndef PAGEBLOCK_FLAGS_H #define PAGEBLOCK_FLAGS_H #include <linux/types.h> /* Bit indices that affect a whole block of pages */ enum pageblock_bits { PB_migrate, PB_migrate_end = PB_migrate + 3 - 1, /* 3 bits required for migrate types */ #ifdef CONFIG_COMPACTION PB_migrate_skip,/* If set the block is skipped by compaction */ #endif /* CONFIG_COMPACTION */ NR_PAGEBLOCK_BITS }; #ifdef CONFIG_HUGETLB_PAGE #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE /* Huge page sizes are variable */ extern int pageblock_order; #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ /* Huge pages are a constant size */ #define pageblock_order HUGETLB_PAGE_ORDER #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ #else /* CONFIG_HUGETLB_PAGE */ /* If huge pages are not used, group by MAX_ORDER_NR_PAGES */ #define pageblock_order (MAX_ORDER-1) #endif /* CONFIG_HUGETLB_PAGE */ #define pageblock_nr_pages (1UL << pageblock_order) /* Forward declaration */ struct page; /* Declarations for getting and setting flags. See mm/page_alloc.c */ unsigned long get_pageblock_flags_group(struct page *page, int start_bitidx, int end_bitidx); void set_pageblock_flags_group(struct page *page, unsigned long flags, int start_bitidx, int end_bitidx); #ifdef CONFIG_COMPACTION #define get_pageblock_skip(page) \ get_pageblock_flags_group(page, PB_migrate_skip, \ PB_migrate_skip) #define clear_pageblock_skip(page) \ set_pageblock_flags_group(page, 0, PB_migrate_skip, \ PB_migrate_skip) #define set_pageblock_skip(page) \ set_pageblock_flags_group(page, 1, PB_migrate_skip, \ PB_migrate_skip) #endif /* CONFIG_COMPACTION */ #endif /* PAGEBLOCK_FLAGS_H */