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| author | Vivek Goyal <vgoyal@in.ibm.com> | 2006-03-25 16:31:16 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-25 09:10:57 -0800 |
| commit | da7ed9f98f6f3f18664f8ab24303f9428b9d78f8 (patch) | |
| tree | 692653ace76f945b130eeb991b8e3857caf866b6 /include | |
| parent | b1fc513d81b0f50f9543428ce95ec63ae70ab184 (diff) | |
| download | lwn-da7ed9f98f6f3f18664f8ab24303f9428b9d78f8.tar.gz lwn-da7ed9f98f6f3f18664f8ab24303f9428b9d78f8.zip | |
[PATCH] x86_64: timer interrupt lockup due to pending interrupt
o check_timer() routine fails while second kernel is booting after a crash
on an opetron box. Problem happens because timer vector (0x31) seems to be
locked.
o After a system crash, it is not safe to service interrupts any more, hence
interrupts are disabled. This leads to pending interrupts at LAPIC. LAPIC
sends these interrupts to the CPU during early boot of second kernel. Other
pending interrupts are discarded saying unexpected trap but timer interrupt
is serviced and CPU does not issue an LAPIC EOI because it think this
interrupt came from i8259 and sends ack to 8259. This leads to vector 0x31
locking as LAPIC does not clear respective ISR and keeps on waiting for
EOI.
o This patch issues extra EOI for the pending interrupts who have ISR set.
o Though today only timer seems to be the special case because in early
boot it thinks interrupts are coming from i8259 and uses
mask_and_ack_8259A() as ack handler and does not issue LAPIC EOI. But
probably doing it in generic manner for all vectors makes sense.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-x86_64/apicdef.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/asm-x86_64/apicdef.h b/include/asm-x86_64/apicdef.h index decaa2d540e8..5a48e9bcf218 100644 --- a/include/asm-x86_64/apicdef.h +++ b/include/asm-x86_64/apicdef.h @@ -39,6 +39,7 @@ #define APIC_SPIV_FOCUS_DISABLED (1<<9) #define APIC_SPIV_APIC_ENABLED (1<<8) #define APIC_ISR 0x100 +#define APIC_ISR_NR 0x8 /* Number of 32 bit ISR registers. */ #define APIC_TMR 0x180 #define APIC_IRR 0x200 #define APIC_ESR 0x280 |