Commit:     4e77ae3e105d28aa9410585715d83818f0abe871
Parent:     b8ce33590687888ebb900d09557b8807c4539022
Author:     Thomas Gleixner <[EMAIL PROTECTED]>
AuthorDate: Fri Oct 12 23:04:07 2007 +0200
Committer:  Thomas Gleixner <[EMAIL PROTECTED]>
CommitDate: Fri Oct 12 23:04:07 2007 +0200

    x86: Fix irq0 / local apic timer accounting
    The clock events merge introduced a change to the nmi watchdog code to
    handle the not longer increasing local apic timer count in the
    broadcast mode. This is fine for UP, but on SMP it pampers over a
    stuck CPU which is not handling the broadcast interrupt due to the
    unconditional sum up of local apic timer count and irq0 count.
    To cover all cases we need to keep track on which CPU irq0 is
    handled. In theory this is CPU#0 due to the explicit disabling of irq
    balancing for irq0, but there are systems which ignore this on the
    hardware level. The per cpu irq0 accounting allows us to remove the
    irq0 to CPU0 binding as well.
    Add a per cpu counter for irq0 and evaluate this instead of the global
    irq0 count in the nmi watchdog code.
    Signed-off-by: Thomas Gleixner <[EMAIL PROTECTED]>
    Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]>
    Signed-off-by: Arjan van de Ven <[EMAIL PROTECTED]>
 arch/x86/kernel/nmi_64.c  |    2 +-
 arch/x86/kernel/time_64.c |    2 ++
 include/asm-x86/pda.h     |    1 +
 3 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/nmi_64.c b/arch/x86/kernel/nmi_64.c
index 0ec6d2d..e60ac0d 100644
--- a/arch/x86/kernel/nmi_64.c
+++ b/arch/x86/kernel/nmi_64.c
@@ -329,7 +329,7 @@ int __kprobes nmi_watchdog_tick(struct pt_regs * regs, 
unsigned reason)
                touched = 1;
-       sum = read_pda(apic_timer_irqs);
+       sum = read_pda(apic_timer_irqs) + read_pda(irq0_irqs);
        if (__get_cpu_var(nmi_touch)) {
                __get_cpu_var(nmi_touch) = 0;
                touched = 1;
diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c
index 7781df1..16f5888 100644
--- a/arch/x86/kernel/time_64.c
+++ b/arch/x86/kernel/time_64.c
@@ -194,6 +194,8 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id)
 static irqreturn_t timer_event_interrupt(int irq, void *dev_id)
+       add_pda(irq0_irqs, 1);
        return IRQ_HANDLED;
diff --git a/include/asm-x86/pda.h b/include/asm-x86/pda.h
index 5642634..fb49f80 100644
--- a/include/asm-x86/pda.h
+++ b/include/asm-x86/pda.h
@@ -29,6 +29,7 @@ struct x8664_pda {
        short isidle;
        struct mm_struct *active_mm;
        unsigned apic_timer_irqs;
+       unsigned irq0_irqs;
 } ____cacheline_aligned_in_smp;
 extern struct x8664_pda *_cpu_pda[];
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