forked from mirrors/linux
		
	In the free path we calculate page_to_pfn multiple times. Reduce that. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			101 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			101 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Macros for manipulating and testing flags related to a
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 * pageblock_nr_pages number of pages.
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation version 2 of the License
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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 *
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 * Copyright (C) IBM Corporation, 2006
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 *
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 * Original author, Mel Gorman
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 * Major cleanups and reduction of bit operations, Andy Whitcroft
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 */
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#ifndef PAGEBLOCK_FLAGS_H
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#define PAGEBLOCK_FLAGS_H
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#include <linux/types.h>
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/* Bit indices that affect a whole block of pages */
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enum pageblock_bits {
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	PB_migrate,
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	PB_migrate_end = PB_migrate + 3 - 1,
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			/* 3 bits required for migrate types */
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	PB_migrate_skip,/* If set the block is skipped by compaction */
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	/*
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	 * Assume the bits will always align on a word. If this assumption
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	 * changes then get/set pageblock needs updating.
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	 */
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	NR_PAGEBLOCK_BITS
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};
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#ifdef CONFIG_HUGETLB_PAGE
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#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
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/* Huge page sizes are variable */
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extern int pageblock_order;
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#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
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/* Huge pages are a constant size */
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#define pageblock_order		HUGETLB_PAGE_ORDER
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#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
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#else /* CONFIG_HUGETLB_PAGE */
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/* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
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#define pageblock_order		(MAX_ORDER-1)
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#endif /* CONFIG_HUGETLB_PAGE */
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#define pageblock_nr_pages	(1UL << pageblock_order)
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/* Forward declaration */
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struct page;
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unsigned long get_pfnblock_flags_mask(struct page *page,
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				unsigned long pfn,
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				unsigned long end_bitidx,
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				unsigned long mask);
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void set_pfnblock_flags_mask(struct page *page,
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				unsigned long flags,
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				unsigned long pfn,
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				unsigned long end_bitidx,
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				unsigned long mask);
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/* Declarations for getting and setting flags. See mm/page_alloc.c */
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#define get_pageblock_flags_group(page, start_bitidx, end_bitidx) \
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	get_pfnblock_flags_mask(page, page_to_pfn(page),		\
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			end_bitidx,					\
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			(1 << (end_bitidx - start_bitidx + 1)) - 1)
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#define set_pageblock_flags_group(page, flags, start_bitidx, end_bitidx) \
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	set_pfnblock_flags_mask(page, flags, page_to_pfn(page),		\
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			end_bitidx,					\
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			(1 << (end_bitidx - start_bitidx + 1)) - 1)
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#ifdef CONFIG_COMPACTION
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#define get_pageblock_skip(page) \
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			get_pageblock_flags_group(page, PB_migrate_skip,     \
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							PB_migrate_skip)
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#define clear_pageblock_skip(page) \
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			set_pageblock_flags_group(page, 0, PB_migrate_skip,  \
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							PB_migrate_skip)
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#define set_pageblock_skip(page) \
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			set_pageblock_flags_group(page, 1, PB_migrate_skip,  \
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							PB_migrate_skip)
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#endif /* CONFIG_COMPACTION */
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#endif	/* PAGEBLOCK_FLAGS_H */
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