From b2fea988f4f3b38ff4edfc1556a843c91932804c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 12 Jul 2011 10:46:31 +0200 Subject: [PATCH] memblock: Improve generic memblock_nid_range() using for_each_mem_pfn_range() Given an address range, memblock_nid_range() determines the node the start of the range belongs to and upto where the range stays in the same node. It's implemented by calling get_pfn_range_for_nid(), which determines min and max pfns for a given node, for each node and testing whether start address falls in there. This is not only inefficient but also incorrect when nodes interleave as min-max ranges for nodes overlap. This patch reimplements memblock_nid_range() using for_each_mem_pfn_range(). It's simpler, walks the mem ranges once and can find the exact range the start address falls in. Signed-off-by: Tejun Heo Link: http://lkml.kernel.org/r/1310460395-30913-5-git-send-email-tj@kernel.org Cc: Yinghai Lu Cc: Benjamin Herrenschmidt Signed-off-by: H. Peter Anvin --- mm/memblock.c | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) diff --git a/mm/memblock.c b/mm/memblock.c index 0f9626f01b5e..97f3486ce4d6 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -511,28 +511,14 @@ phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align) phys_addr_t __weak __init memblock_nid_range(phys_addr_t start, phys_addr_t end, int *nid) { #ifdef CONFIG_ARCH_POPULATES_NODE_MAP - /* - * This code originates from sparc which really wants use to walk by addresses - * and returns the nid. This is not very convenient for early_pfn_map[] users - * as the map isn't sorted yet, and it really wants to be walked by nid. - * - * For now, I implement the inefficient method below which walks the early - * map multiple times. Eventually we may want to use an ARCH config option - * to implement a completely different method for both case. - */ unsigned long start_pfn, end_pfn; int i; - for (i = 0; i < MAX_NUMNODES; i++) { - get_pfn_range_for_nid(i, &start_pfn, &end_pfn); - if (start < PFN_PHYS(start_pfn) || start >= PFN_PHYS(end_pfn)) - continue; - *nid = i; - return min(end, PFN_PHYS(end_pfn)); - } + for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, nid) + if (start >= PFN_PHYS(start_pfn) && start < PFN_PHYS(end_pfn)) + return min(end, PFN_PHYS(end_pfn)); #endif *nid = 0; - return end; } -- 2.30.2