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| author | Vivek Goyal <vgoyal@in.ibm.com> | 2006-05-20 15:00:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-05-21 12:59:20 -0700 |
| commit | be0d03f1c3d3612fe2b6aa451ae87a89382c9231 (patch) | |
| tree | 6449e2071969fda7441437856da6a4739d719851 /arch/i386/kernel | |
| parent | 5daa3ba0c6a41a8bb4ba17ad8d5514172e103504 (diff) | |
| download | linux-be0d03f1c3d3612fe2b6aa451ae87a89382c9231.tar.bz2 | |
[PATCH] i386 kdump boot cpu physical apicid fix
o Kdump second kernel boot fails after a system crash if second kernel
is UP and acpi=off and if crash occurred on a non-boot cpu.
o Issue here is that MP tables report boot cpu lapic id as 0 but second
kernel is booting on a different processor and MP table data is stale
in this context. Hence apic_id_registered() check fails in setup_local_APIC()
when called from APIC_init_uniprocessor().
o Problem is not seen if ACPI is enabled as in that case
boot_cpu_physical_apicid is read from the LAPIC.
o Problem is not seen with SMP kernels as well because in this case also
boot_cpu_physical_apicid is read from LAPIC. (smp_boot_cpus()).
o The problem is fixed by reading boot_cpu_physical_apicid from LAPIC
if it is a UP kernel and CRASH_DUMP is enabled.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386/kernel')
| -rw-r--r-- | arch/i386/kernel/apic.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c index 013b85df18c6..3d4b2f3d116a 100644 --- a/arch/i386/kernel/apic.c +++ b/arch/i386/kernel/apic.c @@ -1341,6 +1341,14 @@ int __init APIC_init_uniprocessor (void) connect_bsp_APIC(); + /* + * Hack: In case of kdump, after a crash, kernel might be booting + * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid + * might be zero if read from MP tables. Get it from LAPIC. + */ +#ifdef CONFIG_CRASH_DUMP + boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID)); +#endif phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid); setup_local_APIC(); |