[RFC][PATCH 3/5] x86: Allow specifying node_distance() for numa=fake

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

[-- Attachment #1: x86-numa-emulation.patch --]
[-- Type: text/plain, Size: 1592 bytes --]

Allows emulating more interesting NUMA configurations like a quad
socket AMD Magny-Cour:

 "numa=fake=8:10,16,16,22,16,22,16,22,
              16,10,22,16,22,16,22,16,
              16,22,10,16,16,22,16,22,
              22,16,16,10,22,16,22,16,
              16,22,16,22,10,16,16,22,
              22,16,22,16,16,10,22,16,
              16,22,16,22,16,22,10,16,
              22,16,22,16,22,16,16,10"

Which has a non-fully-connected topology.

Cc: Tejun Heo <tj@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: x86@kernel.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 arch/x86/mm/numa_emulation.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Index: linux-2.6/arch/x86/mm/numa_emulation.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/numa_emulation.c
+++ linux-2.6/arch/x86/mm/numa_emulation.c
@@ -339,9 +339,11 @@ void __init numa_emulation(struct numa_m
 	} else {
 		unsigned long n;
 
-		n = simple_strtoul(emu_cmdline, NULL, 0);
+		n = simple_strtoul(emu_cmdline, &emu_cmdline, 0);
 		ret = split_nodes_interleave(&ei, &pi, 0, max_addr, n);
 	}
+	if (*emu_cmdline == ':')
+		emu_cmdline++;
 
 	if (ret < 0)
 		goto no_emu;
@@ -418,7 +420,9 @@ void __init numa_emulation(struct numa_m
 			int physj = emu_nid_to_phys[j];
 			int dist;
 
-			if (physi >= numa_dist_cnt || physj >= numa_dist_cnt)
+			if (get_option(&emu_cmdline, &dist) == 2)
+				;
+			else if (physi >= numa_dist_cnt || physj >= numa_dist_cnt)
 				dist = physi == physj ?
 					LOCAL_DISTANCE : REMOTE_DISTANCE;
 			else