Messages in this thread | | | Date | Sat, 25 Jan 2014 08:41:07 +0100 | From | Ingo Molnar <> | Subject | Re: disabled APICs being counted as processors ? |
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* Dave Jones <davej@redhat.com> wrote:
> I have a system with 4 cores (configured with CONFIG_NR_CPUS=4) that shows during boot.. > > [ 0.000000] smpboot: 8 Processors exceeds NR_CPUS limit of 4 > > it looks like this is because.. > > [ 0.000000] ACPI: LAPIC (acpi_id[0x01] lapic_id[0x00] enabled) > [ 0.000000] ACPI: LAPIC (acpi_id[0x02] lapic_id[0x02] enabled) > [ 0.000000] ACPI: LAPIC (acpi_id[0x03] lapic_id[0x04] enabled) > [ 0.000000] ACPI: LAPIC (acpi_id[0x04] lapic_id[0x06] enabled) > [ 0.000000] ACPI: LAPIC (acpi_id[0x05] lapic_id[0xff] disabled) > [ 0.000000] ACPI: LAPIC (acpi_id[0x06] lapic_id[0xff] disabled) > [ 0.000000] ACPI: LAPIC (acpi_id[0x07] lapic_id[0xff] disabled) > [ 0.000000] ACPI: LAPIC (acpi_id[0x08] lapic_id[0xff] disabled) > > Should the CPU counting code be ignoring those disabled APICs ?
Hm, so to the kernel it looks like as if those were 'possible CPUs', in theory hotpluggable. Not sure what they are - disabled cores in an 8-core system? Or BIOS reporting crap?
But perhaps the boot message could be improved to say something like:
> [ 0.000000] smpboot: 8 possible processors exceeds NR_CPUS limit of 4
?
Thanks,
Ingo
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