From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 1 Feb 2010 17:34:06 +1100 From: Anton Blanchard To: benh@kernel.crashing.org Subject: [PATCH 5/7] powerpc: Add timer, performance monitor and machine check counts to /proc/interrupts Message-ID: <20100201063406.GX2996@kryten> References: <20100201063023.GT2996@kryten> <20100201063251.GU2996@kryten> <20100201063318.GV2996@kryten> <20100201063341.GW2996@kryten> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20100201063341.GW2996@kryten> Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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: Anton Blanchard --- If people really don't like the x86 short names, we can think up something else. Index: linux-cpumask/arch/powerpc/include/asm/hardirq.h =================================================================== --- linux-cpumask.orig/arch/powerpc/include/asm/hardirq.h 2010-02-01 17:28:56.990963256 +1100 +++ linux-cpumask/arch/powerpc/include/asm/hardirq.h 2010-02-01 17:29:03.887211643 +1100 @@ -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 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 */ Index: linux-cpumask/arch/powerpc/kernel/time.c =================================================================== --- linux-cpumask.orig/arch/powerpc/kernel/time.c 2010-02-01 17:28:56.590961781 +1100 +++ linux-cpumask/arch/powerpc/kernel/time.c 2010-02-01 17:29:03.887211643 +1100 @@ -575,6 +575,8 @@ void timer_interrupt(struct pt_regs * re 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); Index: linux-cpumask/arch/powerpc/kernel/irq.c =================================================================== --- linux-cpumask.orig/arch/powerpc/kernel/irq.c 2010-02-01 17:29:02.007212291 +1100 +++ linux-cpumask/arch/powerpc/kernel/irq.c 2010-02-01 17:29:03.887211643 +1100 @@ -196,6 +196,21 @@ static int show_other_interrupts(struct } #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) { Index: linux-cpumask/arch/powerpc/kernel/traps.c =================================================================== --- linux-cpumask.orig/arch/powerpc/kernel/traps.c 2010-02-01 17:28:56.570961322 +1100 +++ linux-cpumask/arch/powerpc/kernel/traps.c 2010-02-01 17:29:03.897211396 +1100 @@ -478,6 +478,8 @@ void machine_check_exception(struct pt_r { 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 @@ -960,6 +962,8 @@ void vsx_unavailable_exception(struct pt void performance_monitor_exception(struct pt_regs *regs) { + __get_cpu_var(irq_stat).pmu_irqs++; + perf_irq(regs); }