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authorAnton Blanchard <anton@samba.org>2010-01-31 20:34:36 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2010-02-17 14:02:49 +1100
commit17081102a6e0fe32cf47cdbdf8f2e9ab55273b08 (patch)
tree6bbe3f22d4414598cdfdb69510f0679b90c68175
parent89713ed10815401a1bfe12e3a076b64048381b56 (diff)
downloadblackbird-op-linux-17081102a6e0fe32cf47cdbdf8f2e9ab55273b08.tar.gz
blackbird-op-linux-17081102a6e0fe32cf47cdbdf8f2e9ab55273b08.zip
powerpc: Convert global "BAD" interrupt to per cpu spurious
I often get asked if BAD interrupts are really bad. On some boxes (eg IBM machines running a hypervisor) there are valid cases where are presented with an interrupt that is not for us. These cases are common enough to show up as thousands of BAD interrupts a day. Tone them down by calling them spurious. Since they can be a significant cause of OS jitter, we may as well log them per cpu so we know where they are occurring. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/include/asm/hardirq.h4
-rw-r--r--arch/powerpc/kernel/irq.c19
2 files changed, 8 insertions, 15 deletions
diff --git a/arch/powerpc/include/asm/hardirq.h b/arch/powerpc/include/asm/hardirq.h
index cd2d4be882aa..3147a2970125 100644
--- a/arch/powerpc/include/asm/hardirq.h
+++ b/arch/powerpc/include/asm/hardirq.h
@@ -9,6 +9,7 @@ typedef struct {
unsigned int timer_irqs;
unsigned int pmu_irqs;
unsigned int mce_exceptions;
+ unsigned int spurious_irqs;
} ____cacheline_aligned irq_cpustat_t;
DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
@@ -25,7 +26,4 @@ static inline void ack_bad_irq(unsigned int irq)
extern u64 arch_irq_stat_cpu(unsigned int cpu);
#define arch_irq_stat_cpu arch_irq_stat_cpu
-extern u64 arch_irq_stat(void);
-#define arch_irq_stat arch_irq_stat
-
#endif /* _ASM_POWERPC_HARDIRQ_H */
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 710505240f2f..9ae77e52f9d3 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -77,7 +77,6 @@ DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
EXPORT_PER_CPU_SYMBOL(irq_stat);
int __irq_offset_value;
-static int ppc_spurious_interrupts;
#ifdef CONFIG_PPC32
EXPORT_SYMBOL(__irq_offset_value);
@@ -201,6 +200,11 @@ static int show_other_interrupts(struct seq_file *p, int prec)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
seq_printf(p, " Local timer interrupts\n");
+ seq_printf(p, "%*s: ", prec, "SPU");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
+ seq_printf(p, " Spurious interrupts\n");
+
seq_printf(p, "%*s: ", prec, "CNT");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
@@ -211,8 +215,6 @@ static int show_other_interrupts(struct seq_file *p, int prec)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
seq_printf(p, " Machine check exceptions\n");
- seq_printf(p, "%*s: %10u\n", prec, "BAD", ppc_spurious_interrupts);
-
return 0;
}
@@ -282,13 +284,7 @@ u64 arch_irq_stat_cpu(unsigned int cpu)
sum += per_cpu(irq_stat, cpu).pmu_irqs;
sum += per_cpu(irq_stat, cpu).mce_exceptions;
-
- return sum;
-}
-
-u64 arch_irq_stat(void)
-{
- u64 sum = ppc_spurious_interrupts;
+ sum += per_cpu(irq_stat, cpu).spurious_irqs;
return sum;
}
@@ -404,8 +400,7 @@ void do_IRQ(struct pt_regs *regs)
if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
handle_one_irq(irq);
else if (irq != NO_IRQ_IGNORE)
- /* That's not SMP safe ... but who cares ? */
- ppc_spurious_interrupts++;
+ __get_cpu_var(irq_stat).spurious_irqs++;
irq_exit();
set_irq_regs(old_regs);
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