From 53fee04f318222a3179ca5933d8bda82c1eef17a Mon Sep 17 00:00:00 2001 From: Rohit Seth Date: Tue, 13 Feb 2007 13:26:22 +0100 Subject: [PATCH] x86-64: Fix fake numa for x86_64 machines with big IO hole This patch resolves the issue of running with numa=fake=X on kernel command line on x86_64 machines that have big IO hole. While calculating the size of each node now we look at the total hole size in that range. Previously there were nodes that only had IO holes in them causing kernel boot problems. We now use the NODE_MIN_SIZE (64MB) as the minimum size of memory that any node must have. We reduce the number of allocated nodes if the number of nodes specified on kernel command line results in any node getting memory smaller than NODE_MIN_SIZE. This change allows the extra memory to be incremented in NODE_MIN_SIZE granule and uniformly distribute among as many nodes (called big nodes) as possible. [akpm@osdl.org: build fix] Signed-off-by: David Rientjes Signed-off-by: Paul Menage Signed-off-by: Rohit Seth Signed-off-by: Andi Kleen Cc: Andi Kleen Signed-off-by: Andrew Morton --- arch/x86_64/kernel/e820.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'arch/x86_64/kernel') diff --git a/arch/x86_64/kernel/e820.c b/arch/x86_64/kernel/e820.c index 9d67955bbc3..4651fd22b21 100644 --- a/arch/x86_64/kernel/e820.c +++ b/arch/x86_64/kernel/e820.c @@ -190,6 +190,37 @@ unsigned long __init e820_end_of_ram(void) return end_pfn; } +/* + * Find the hole size in the range. + */ +unsigned long __init e820_hole_size(unsigned long start, unsigned long end) +{ + unsigned long ram = 0; + int i; + + for (i = 0; i < e820.nr_map; i++) { + struct e820entry *ei = &e820.map[i]; + unsigned long last, addr; + + if (ei->type != E820_RAM || + ei->addr+ei->size <= start || + ei->addr >= end) + continue; + + addr = round_up(ei->addr, PAGE_SIZE); + if (addr < start) + addr = start; + + last = round_down(ei->addr + ei->size, PAGE_SIZE); + if (last >= end) + last = end; + + if (last > addr) + ram += last - addr; + } + return ((end - start) - ram); +} + /* * Mark e820 reserved areas as busy for the resource manager. */ -- cgit v1.2.3