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Commit 89713ed1 authored by Anton Blanchard's avatar Anton Blanchard Committed by Benjamin Herrenschmidt
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powerpc: Add timer, performance monitor and machine check counts to /proc/interrupts 



With NO_HZ it is useful to know how often the decrementer is going off. The
patch below adds an entry for it and also adds it into the /proc/stat
summaries.

While here, I added performance monitoring and machine check exceptions.
I found it useful to keep an eye on the PMU exception rate
when using the perf tool. Since it's possible to take a completely
handled machine check on a System p box it also sounds like a good idea to
keep a machine check summary.

The event naming matches x86 to keep gratuitous differences to a minimum.

Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent fc380c0c

arch/powerpc/include/asm/hardirq.h

+9 −0
Original line number Diff line number Diff line
@@ -6,6 +6,9 @@ 


typedef struct {

	unsigned int __softirq_pending;

	unsigned int timer_irqs;

	unsigned int pmu_irqs;

	unsigned int mce_exceptions;

} ____cacheline_aligned irq_cpustat_t;



DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
@@ -19,4 +22,10 @@ static inline void ack_bad_irq(unsigned int irq) 
	printk(KERN_CRIT "unexpected IRQ trap at vector %02x\n", 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 */

arch/powerpc/kernel/irq.c

+35 −0
Original line number Diff line number Diff line
@@ -196,6 +196,21 @@ static int show_other_interrupts(struct seq_file *p, int prec) 
	}

#endif /* CONFIG_PPC32 && CONFIG_TAU_INT */



	seq_printf(p, "%*s: ", prec, "LOC");

	for_each_online_cpu(j)

		seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);

        seq_printf(p, "  Local timer interrupts\n");



	seq_printf(p, "%*s: ", prec, "CNT");

	for_each_online_cpu(j)

		seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);

	seq_printf(p, "  Performance monitoring interrupts\n");



	seq_printf(p, "%*s: ", prec, "MCE");

	for_each_online_cpu(j)

		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;
@@ -258,6 +273,26 @@ out: 
	return 0;

}



/*

 * /proc/stat helpers

 */

u64 arch_irq_stat_cpu(unsigned int cpu)

{

	u64 sum = per_cpu(irq_stat, cpu).timer_irqs;



	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;



	return sum;

}



#ifdef CONFIG_HOTPLUG_CPU

void fixup_irqs(cpumask_t map)

{

arch/powerpc/kernel/time.c

+2 −0
Original line number Diff line number Diff line
@@ -575,6 +575,8 @@ void timer_interrupt(struct pt_regs * regs) 


	trace_timer_interrupt_entry(regs);



	__get_cpu_var(irq_stat).timer_irqs++;



	/* Ensure a positive value is written to the decrementer, or else

	 * some CPUs will continuue to take decrementer exceptions */

	set_dec(DECREMENTER_MAX);

arch/powerpc/kernel/traps.c

+4 −0
Original line number Diff line number Diff line
@@ -483,6 +483,8 @@ void machine_check_exception(struct pt_regs *regs) 
{

	int recover = 0;



	__get_cpu_var(irq_stat).mce_exceptions++;



	/* See if any machine dependent calls. In theory, we would want

	 * to call the CPU first, and call the ppc_md. one if the CPU

	 * one returns a positive number. However there is existing code
@@ -965,6 +967,8 @@ void vsx_unavailable_exception(struct pt_regs *regs) 


void performance_monitor_exception(struct pt_regs *regs)

{

	__get_cpu_var(irq_stat).pmu_irqs++;



	perf_irq(regs);

}