From: Andy Whitcroft Date: Sun, 6 May 2007 21:49:14 +0000 (-0700) Subject: add pfn_valid_within helper for sub-MAX_ORDER hole detection X-Git-Tag: v2.6.22-rc1~986 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=14e072984179d3d421bf9ab75cc67e0961742841;p=pandora-kernel.git 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 Acked-by: Mel Gorman Acked-by: Bob Picco Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed