Messages in this thread |  | | Date | Sat, 21 Feb 2009 14:43:46 -0800 | | From | Yinghai Lu <> | | Subject | Re: [PATCH] x86: enable x2apic early at the first point |
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Suresh Siddha wrote: > On Fri, 2009-02-20 at 01:55 -0800, Ingo Molnar wrote: >> * Ingo Molnar <mingo@elte.hu> wrote: >> >>>> arch/x86/kernel/apic/apic.c | 3 +-- >>>> arch/x86/kernel/apic/x2apic_cluster.c | 5 ++++- >>>> arch/x86/kernel/apic/x2apic_phys.c | 5 ++++- >>>> arch/x86/kernel/apic/x2apic_uv_x.c | 4 +++- >>>> drivers/pci/dmar.c | 3 ++- >>>> 5 files changed, 14 insertions(+), 6 deletions(-) >>> I've applied it because it fixes a real bug, but this code >>> really needs a cleanup. Look at the repeat patterns: >> unapplied it again as it breaks the build: >> >> arch/x86/kernel/apic/x2apic_cluster.c: In function 'x2apic_acpi_madt_oem_check': >> arch/x86/kernel/apic/x2apic_cluster.c:17: error: 'disable_x2apic' undeclared (first use in this function) >> arch/x86/kernel/apic/x2apic_cluster.c:17: error: (Each undeclared identifier is reported only once >> arch/x86/kernel/apic/x2apic_cluster.c:17: error: for each function it appears in.) >> >> so please resend the fixed and cleaned up version. > > From: Suresh Siddha <suresh.b.siddha@intel.com> > Subject: x86: select x2apic ops in early apic probe only if x2apic mode is enabled > > If BIOS hands over the control to OS in legacy xapic mode, select legacy xapic > related ops in the early apic probe and shift to x2apic ops later in the boot > sequence, only after enabling x2apic mode. > > If BIOS hands over the control in x2apic mode, select x2apic related ops > in the early apic probe. > > This fixes the early boot panic, where we were selecting x2apic ops, > while the cpu is still in legacy xapic mode.
good, other than that.
for x2apic preenabled system, when nox2apic is used, cpu_has_x2apic will be cleared, apic will be xapic phys_flat or flat. is that expected?
should 1. ignore nox2apic 2. or try to disable x2apic?
YH
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