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| author | Michel Lespinasse <walken@google.com> | 2012-12-12 04:01:49 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-12 05:22:25 +0400 |
| commit | db4fbfb9523c93583c339e66023506f651c1d54b (patch) | |
| tree | 8dfc250bb2249feaafe27c11cc4de5a654815833 /include/linux/mm.h | |
| parent | e4c6bfd2d79d063017ab19a18915f0bc759f32d9 (diff) | |
| download | linux-db4fbfb9523c93583c339e66023506f651c1d54b.tar.xz | |
mm: vm_unmapped_area() lookup function
Implement vm_unmapped_area() using the rb_subtree_gap and highest_vm_end
information to look up for suitable virtual address space gaps.
struct vm_unmapped_area_info is used to define the desired allocation
request:
- lowest or highest possible address matching the remaining constraints
- desired gap length
- low/high address limits that the gap must fit into
- alignment mask and offset
Also update the generic arch_get_unmapped_area[_topdown] functions to make
use of vm_unmapped_area() instead of implementing a brute force search.
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index bcaab4e6fe91..4af4f0b1be4c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1456,6 +1456,37 @@ extern unsigned long vm_mmap(struct file *, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); +struct vm_unmapped_area_info { +#define VM_UNMAPPED_AREA_TOPDOWN 1 + unsigned long flags; + unsigned long length; + unsigned long low_limit; + unsigned long high_limit; + unsigned long align_mask; + unsigned long align_offset; +}; + +extern unsigned long unmapped_area(struct vm_unmapped_area_info *info); +extern unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info); + +/* + * Search for an unmapped address range. + * + * We are looking for a range that: + * - does not intersect with any VMA; + * - is contained within the [low_limit, high_limit) interval; + * - is at least the desired size. + * - satisfies (begin_addr & align_mask) == (align_offset & align_mask) + */ +static inline unsigned long +vm_unmapped_area(struct vm_unmapped_area_info *info) +{ + if (!(info->flags & VM_UNMAPPED_AREA_TOPDOWN)) + return unmapped_area(info); + else + return unmapped_area_topdown(info); +} + /* truncate.c */ extern void truncate_inode_pages(struct address_space *, loff_t); extern void truncate_inode_pages_range(struct address_space *, |