Commit db4fbfb9 authored by Michel Lespinasse's avatar Michel Lespinasse Committed by Linus Torvalds

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: default avatarMichel Lespinasse <walken@google.com>
Reviewed-by: default avatarRik 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e4c6bfd2
...@@ -1456,6 +1456,37 @@ extern unsigned long vm_mmap(struct file *, unsigned long, ...@@ -1456,6 +1456,37 @@ extern unsigned long vm_mmap(struct file *, unsigned long,
unsigned long, unsigned long, unsigned long, 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 */ /* truncate.c */
extern void truncate_inode_pages(struct address_space *, loff_t); extern void truncate_inode_pages(struct address_space *, loff_t);
extern void truncate_inode_pages_range(struct address_space *, extern void truncate_inode_pages_range(struct address_space *,
......
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