Messages in this thread Patch in this message | | | Date | Wed, 02 Mar 2011 15:14:58 -0800 | From | Yinghai Lu <> | Subject | [PATCH for.38] x86, numa: Fix numa_emulation code with node0 without RAM |
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On one system that does not have RAM on node0.
when numa_emulation is compiled in, and 1. boot system without numa=fake... 2. or boot system with numa=fake=128 to make emulation fail
will get:
[ 0.076025] ------------[ cut here ]------------ [ 0.080004] kernel BUG at arch/x86/mm/numa_64.c:788! [ 0.080004] invalid opcode: 0000 [#1] SMP [ 0.080004] last sysfs file: [ 0.080004] CPU 0 [ 0.080004] Modules linked in: [ 0.080004] [ 0.080004] Pid: 0, comm: swapper Not tainted 2.6.38-rc6-yh-00212-g3e1f235 #1 Sun Microsystems Sun Fire X4240/Sun Fire X4240 [ 0.080004] RIP: 0010:[<ffffffff81cd1d8c>] [<ffffffff81cd1d8c>] numa_add_cpu+0x8a/0x156 ... [ 0.080004] Call Trace: [ 0.080004] [<ffffffff81ccd1cd>] identify_cpu+0x2d7/0x2df [ 0.080004] [<ffffffff827e13e9>] identify_boot_cpu+0x10/0x30 [ 0.080004] [<ffffffff827e15f3>] check_bugs+0x9/0x2d [ 0.080004] [<ffffffff827d9bcb>] start_kernel+0x3bf/0x3d9 [ 0.080004] [<ffffffff827d92a6>] x86_64_start_reservations+0xb6/0xba [ 0.080004] [<ffffffff827d93a1>] x86_64_start_kernel+0xf7/0xfe [ 0.080004] Code: 74 06 48 8d 04 90 eb 0f 48 c7 c0 10 d9 00 00 48 03 04 d5 50 e1 5f 82 8b 00 83 f8 ff 74 0d 0f a3 05 7a f9 92 00 19 d2 85 d2 75 02 <0f> 0b 48 98 31 db 48 8b 04 c5 d0 ec 5f 82 48 8b 90 90 af 00 00
need to used early_cpu_to_node directly, because cpu_to_apicid and apicid_to_node will return node0 that is not onlined.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
--- arch/x86/mm/numa_64.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
Index: linux-2.6/arch/x86/mm/numa_64.c =================================================================== --- linux-2.6.orig/arch/x86/mm/numa_64.c +++ linux-2.6/arch/x86/mm/numa_64.c @@ -780,11 +780,7 @@ void __cpuinit numa_add_cpu(int cpu) int physnid; int nid = NUMA_NO_NODE; - apicid = early_per_cpu(x86_cpu_to_apicid, cpu); - if (apicid != BAD_APICID) - nid = apicid_to_node[apicid]; - if (nid == NUMA_NO_NODE) - nid = early_cpu_to_node(cpu); + nid = early_cpu_to_node(cpu); BUG_ON(nid == NUMA_NO_NODE || !node_online(nid)); /*
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