diff options
author | Andy Whitcroft <apw@shadowen.org> | 2007-05-06 14:49:14 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-07 12:12:52 -0700 |
commit | 14e072984179d3d421bf9ab75cc67e0961742841 (patch) | |
tree | 65a5a6f7d9756b8e7010278b58908d04da257a28 /mm/memory.c | |
parent | ac267728f13c55017ed5ee243c9c3166e27ab929 (diff) |
add pfn_valid_within helper for sub-MAX_ORDER hole detection
Generally we work under the assumption that memory the mem_map array is
contigious and valid out to MAX_ORDER_NR_PAGES block of pages, ie. that if we
have validated any page within this MAX_ORDER_NR_PAGES block we need not check
any other. This is not true when CONFIG_HOLES_IN_ZONE is set and we must
check each and every reference we make from a pfn.
Add a pfn_valid_within() helper which should be used when scanning pages
within a MAX_ORDER_NR_PAGES block when we have already checked the validility
of the block normally with pfn_valid(). This can then be optimised away when
we do not have holes within a MAX_ORDER_NR_PAGES block of pages.
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
0 files changed, 0 insertions, 0 deletions