SMP K7 boxes that run in UP mode, because they have only one CPU
installed or are running a UP kernel, are prone to instability
due to APIC bus problems.
These problems occur because the kernel's local APIC code always
resets the boot CPU's APIC_ID to zero, due to a combination of a
programming error and a logical mistake. Since some dual K7 boards
boot on the non-zero APIC_ID CPU, this bogus reset creates an APIC_ID
conflict which causes APIC bus errors and message delivery failures.
The patch below fixes this. The same fix went into 2.5.64. Please apply.
/Mikael
--- linux-2.4.21-pre7/arch/i386/kernel/apic.c.~1~ 2003-04-05 12:35:30.000000000 +0200
+++ linux-2.4.21-pre7/arch/i386/kernel/apic.c 2003-04-05 13:10:51.000000000 +0200
@@ -649,7 +649,6 @@
}
set_bit(X86_FEATURE_APIC, &boot_cpu_data.x86_capability);
mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
- boot_cpu_physical_apicid = 0;
if (nmi_watchdog != NMI_NONE)
nmi_watchdog = NMI_LOCAL_APIC;
@@ -1169,8 +1168,7 @@
connect_bsp_APIC();
- phys_cpu_present_map = 1;
- apic_write_around(APIC_ID, boot_cpu_physical_apicid);
+ phys_cpu_present_map = 1 << boot_cpu_physical_apicid;
apic_pm_init2();
-
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This archive was generated by hypermail 2b29 : Mon Apr 07 2003 - 22:00:25 EST