mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-27 06:34:11 +08:00
c801ed3860
The use of #defines with '##' pre-processor concatenation is a useful way to form several symbol names with a common pattern. But when there is just a single name obtained from that #define, it's just obfuscation. Better to just write the plain symbol name, as is. The following patch is a result of my wasting ten minutes looking through the kernel to figure out what 'PB_migrate_end' meant, and forgetting what I came to do, by the time I figured out that the #define PB_range macro defined it. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
74 lines
2.2 KiB
C
74 lines
2.2 KiB
C
/*
|
|
* 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 */
|
|
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);
|
|
|
|
#define get_pageblock_flags(page) \
|
|
get_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1)
|
|
#define set_pageblock_flags(page) \
|
|
set_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1)
|
|
|
|
#endif /* PAGEBLOCK_FLAGS_H */
|