From: Yinghai Lu <yinghai@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
"H. Peter Anvin" <hpa@zytor.com>,
David Rientjes <rientjes@google.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: [PATCH for.38] x86, numa: Fix numa_emulation code with node0 without RAM
Date: Wed, 02 Mar 2011 15:14:58 -0800 [thread overview]
Message-ID: <4D6ECF72.5010308@kernel.org> (raw)
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));
/*
next reply other threads:[~2011-03-02 23:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-02 23:14 Yinghai Lu [this message]
2011-03-04 13:47 ` [PATCH for.38] x86, numa: Fix numa_emulation code with node0 without RAM Tejun Heo
2011-03-04 14:31 ` [tip:x86/urgent] x86, numa: Fix numa_emulation code with memory-less node0 tip-bot for Yinghai Lu
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