From 4738e1b9cf8f9e28d7de080a5e6ce5d0095ea18f Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 21 Sep 2009 17:03:03 -0700 Subject: [PATCH] memory hotplug: fix updating of num_physpages for hot plugged memory Sizing of memory allocations shouldn't depend on the number of physical pages found in a system, as that generally includes (perhaps a huge amount of) non-RAM pages. The amount of what actually is usable as storage should instead be used as a basis here. In line with that, the memory hotplug code should update num_physpages in a way that it retains its original (post-boot) meaning; in particular, decreasing the value should at best be done with great care - this patch doesn't try to ever decrease this value at all as it doesn't really seem meaningful to do so. Signed-off-by: Jan Beulich Acked-by: Rusty Russell Cc: Yasunori Goto Cc: Badari Pulavarty Cc: Minchan Kim Cc: Mel Gorman Cc: Dave Hansen Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory_hotplug.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 616236e6343f..efe3e0ec2e61 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -339,8 +339,11 @@ EXPORT_SYMBOL_GPL(__remove_pages); void online_page(struct page *page) { + unsigned long pfn = page_to_pfn(page); + totalram_pages++; - num_physpages++; + if (pfn >= num_physpages) + num_physpages = pfn + 1; #ifdef CONFIG_HIGHMEM if (PageHighMem(page)) @@ -832,7 +835,6 @@ int offline_pages(unsigned long start_pfn, zone->present_pages -= offlined_pages; zone->zone_pgdat->node_present_pages -= offlined_pages; totalram_pages -= offlined_pages; - num_physpages -= offlined_pages; setup_per_zone_wmarks(); calculate_zone_inactive_ratio(zone);