From b5445f956ec3c8c19b760775e9ff92a160e3a167 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 26 Jul 2007 10:41:18 -0700 Subject: Allow nodes to exist that only contain ZONE_MOVABLE With the introduction of kernelcore=, a configurable zone is created on request. In some cases, this value will be small enough that some nodes contain only ZONE_MOVABLE. On some NUMA configurations when this occurs, arch-independent zone-sizing will get the size of the memory holes within the node incorrect. The value of present_pages goes negative and the boot fails. This patch fixes the bug in the calculation of the size of the hole. The test case is to boot test a NUMA machine with a low value of kernelcore= before and after the patch is applied. While this bug exists in early kernel it cannot be triggered in practice. This patch has been boot-tested on a variety machines with and without kernelcore= set. Signed-off-by: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 40954fb8159..6d3550ca028 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2775,11 +2775,11 @@ unsigned long __meminit __absent_pages_in_range(int nid, if (i == -1) return 0; + prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn); + /* Account for ranges before physical memory on this node */ if (early_node_map[i].start_pfn > range_start_pfn) - hole_pages = early_node_map[i].start_pfn - range_start_pfn; - - prev_end_pfn = early_node_map[i].start_pfn; + hole_pages = prev_end_pfn - range_start_pfn; /* Find all holes for the zone within the node */ for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { -- cgit v1.2.3