Len, anyone else, Any comments on this one ? This fixes a important bug during cpu hotadd where the kernel fails to recognize all the newly added cpus. Thanks, Alok On Wed, 2012-02-15 at 16:06 -0800, Petr Vandrovec wrote: > From: Petr Vandrovec <petr@xxxxxxxxxx> > > When processor is being hot-added to the system, acpi_map_lsapic invokes > ACPI _MAT method to find APIC ID and flags, verifies that returned structure > is indeed ACPI's local APIC structure, and that flags contain MADT_ENABLED > bit. Then saves APIC ID, frees structure - and accesses structure when > computing arguments for acpi_register_lapic call. Which sometime leads > to acpi_register_lapic call being made with second argument zero, failing > to bring processor online with error 'Unable to map lapic to logical cpu > number'. > > As lapic->lapic_flags & ACPI_MADT_ENABLED was already confirmed to be non-zero > few lines above, we can just pass unconditional ACPI_MADT_ENABLED to the > acpi_register_lapic. > > Thanks, Petr > > Signed-off-by: Petr Vandrovec <petr@xxxxxxxxxx> > Signed-off-by: Alok Kataria <akataria@xxxxxxxxxx> > > > diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c > index ce664f3..a4a0901 100644 > --- a/arch/x86/kernel/acpi/boot.c > +++ b/arch/x86/kernel/acpi/boot.c > @@ -650,7 +650,7 @@ static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int *pcpu) > goto free_tmp_map; > > cpumask_copy(tmp_map, cpu_present_mask); > - acpi_register_lapic(physid, lapic->lapic_flags & ACPI_MADT_ENABLED); > + acpi_register_lapic(physid, ACPI_MADT_ENABLED); > > /* > * If mp_register_lapic successfully generates a new logical cpu -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
