Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Baoquan He <> | Subject | [PATCH] acpi: try to trust cpu_index from x86_cpu_to_apicid | Date | Tue, 15 Apr 2014 07:55:54 +0800 |
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In smp with multi cpus, when enter into kdump kernel with only 1 cpu, a warning message is printed out:
acpi LNXCPU:0a: BIOS reported wrong ACPI id 0 for the processor
In this case kdump kernel use the same ACPI tables as 1st kernel, means lapic information is got from MADT. The acpi_id related to this cpu index and lapic_id may not be 0, so the code to assign value to cpu_index is not correct in this case per cpu0_initialized. cpu index stored in x86_cpu_to_apicid need be respected.
Now fix it in this patch per boot_cpu_physical_apicid. When cpu index related to boot_cpu_physical_apicid is not stored in x86_cpu_to_apicid, then we can say this is UP system running SMP kernel with no LAPIC in MADT
Signed-off-by: Baoquan He <bhe@redhat.com> --- drivers/acpi/acpi_processor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index c29c2c3..1ae460c 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -267,7 +267,7 @@ static int acpi_processor_get_info(struct acpi_device *device) pr->apic_id = apic_id; cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id); - if (!cpu0_initialized) { + if (!cpu0_initialized && (boot_cpu_physical_apicid == pr->apic_id)) { cpu0_initialized = 1; /* Handle UP system running SMP kernel, with no LAPIC in MADT */ if ((cpu_index == -1) && (num_online_cpus() == 1)) -- 1.8.5.3
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