Re: [patch] x86: 2.6.31-rc7 crash due to buggy flat_phys_pkg_id

Yinghai Lu
2009-08-25T00:27:58Z

Yinghai Lu wrote:
> Ravikiran G Thirumalai wrote:
>> 2.6.31-rc7 does not boot on vSMPowered systems. The sched domains
>> seem to build incorrectly with error messages of the sort:
>>
>> [ 8.501108] CPU31: Thermal monitoring enabled (TM1)
>> [ 8.501127] CPU 31 MCA banks SHD:2 SHD:3 SHD:5 SHD:6 SHD:8
>> [ 8.650254] CPU31: Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
>> stepping 04
>> [ 8.710324] Brought up 32 CPUs
>> [ 8.713916] Total of 32 processors activated (162314.96 BogoMIPS).
>> [ 8.721489] ERROR: parent span is not a superset of domain->span
>> [ 8.727686] ERROR: domain->groups does not contain CPU0
>> [ 8.733091] ERROR: groups don't span domain->span
>> [ 8.737975] ERROR: domain->cpu_power not set
>> [ 8.742416]
>>
>> This is followed by oopsen in the scheduler code
>> with NULL pointer deference in find_busiest_group.
>>
>> Git bisection pointed to the following commit:
>>
>> commit 2759c3287de27266e06f1f4e82cbd2d65f6a044c
>> x86: don't call read_apic_id if !cpu_has_apic
>>
>> Upon examining the history of the commit, the above commit seems to be a fix
>> for:
>>
>> commit 4797f6b021a3fa399942245d07a1feb30df81bb8
>> x86: read apic ID in the !acpi_lapic case
>>
>> However, there appears to be bug in the commit
>> 2759c3287de27266e06f1f4e82cbd2d65f6a044c, where flat_phys_pkg_id
>> uses initial apic id instead of hard_smp_processor_id() on SMP machines.
>> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=2759c3287de27266e06f1f4e82cbd2d65f6a044c
>>
>> This patch fixes the bug and causes vSMPowered systems to boot up
>> correctly,

can you check if this one fix your problem?

BTW: what does your /proc/cpuinfo print about apic id and initial apic id?

[PATCH] x86: use read_apic_id to get apic id

and leave phys_proc_id to use initial apic id.

---
arch/x86/kernel/cpu/common.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/common.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/common.c
+++ linux-2.6/arch/x86/kernel/cpu/common.c
@@ -715,7 +715,7 @@ static void __cpuinit generic_identify(s
c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
#ifdef CONFIG_X86_32
# ifdef CONFIG_X86_HT
- c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
+ c->apicid = read_apic_id();
# else
c->apicid = c->initial_apicid;
# endif
@@ -772,7 +772,7 @@ static void __cpuinit identify_cpu(struc
}

#ifdef CONFIG_X86_64
- c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
+ c->apicid = read_apic_id();
#endif

/*