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| author | Ingo Molnar <mingo@elte.hu> | 2007-10-19 20:35:02 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2007-10-19 20:35:02 +0200 |
| commit | 54ffaa45c5f572ff6c344ca583137d0edf2d78cc (patch) | |
| tree | 389a89b03cf4c8197e3ed8ac7af78950251ce235 | |
| parent | 3ceba7815cfc0b5d4c2bef5bb58e0c766da63549 (diff) | |
| download | talos-op-linux-54ffaa45c5f572ff6c344ca583137d0edf2d78cc.tar.gz talos-op-linux-54ffaa45c5f572ff6c344ca583137d0edf2d78cc.zip | |
x86: fix CONFIG_NUMA and nosmp | maxcpus=0/1 crash
x86 NUMA kernels crash in the scheduler setup code if "nosmp" or
"maxcpus=0" is passed on the boot command line:
| Brought up 1 CPUs
| BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000
| printing eip: c011f0b5 *pde = 00000000
| Oops: 0000 [#1] SMP
|
| Pid: 1, comm: swapper Not tainted (2.6.23 #67)
| EIP: 0060:[<c011f0b5>] EFLAGS: 00010246 CPU: 0
| EIP is at sd_degenerate+0x35/0x40
the reason is sloppy spaghetti code in smpboot_32.c that resulted in a
missing map_cpu_to_logical_apicid() call - which also had the side-effect
of setting up the cpu_2_node[] entry for the lone CPU. That resulted in
node_to_cpumask(0) resulting in 00000000 - confusing the sched-domains
setup code.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | arch/x86/kernel/smpboot_32.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/smpboot_32.c b/arch/x86/kernel/smpboot_32.c index be3faac04719..65e5de7d64db 100644 --- a/arch/x86/kernel/smpboot_32.c +++ b/arch/x86/kernel/smpboot_32.c @@ -1008,6 +1008,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus) printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n"); smpboot_clear_io_apic_irqs(); phys_cpu_present_map = physid_mask_of_physid(0); + map_cpu_to_logical_apicid(); cpu_set(0, per_cpu(cpu_sibling_map, 0)); cpu_set(0, per_cpu(cpu_core_map, 0)); return; @@ -1029,6 +1030,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus) } smpboot_clear_io_apic_irqs(); phys_cpu_present_map = physid_mask_of_physid(0); + map_cpu_to_logical_apicid(); cpu_set(0, per_cpu(cpu_sibling_map, 0)); cpu_set(0, per_cpu(cpu_core_map, 0)); return; |
