[RFC PATCH] powerpc: improve accounting of non maskable interrupts
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2017-07-29 13:23:10
This fixes a case of double counting MCEs on PowerNV. Adds a counter for the system reset interrupt, which will see more use as a debugging NMI. Adds a soft-NMI counter for the 64s watchdog. Although this could cause confusion because it only fires when interrupts are soft-disabled, so it won't increment much even when the watchdog is running. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- I can split these out or drop any objectionable bits. At least the MCE we should fix, not sure if the other bits are wanted. Thanks, Nick arch/powerpc/include/asm/hardirq.h | 4 ++++ arch/powerpc/kernel/irq.c | 16 ++++++++++++++++ arch/powerpc/kernel/traps.c | 9 +++++++++ arch/powerpc/kernel/watchdog.c | 3 +++ 4 files changed, 32 insertions(+)
diff --git a/arch/powerpc/include/asm/hardirq.h b/arch/powerpc/include/asm/hardirq.h
index 8add8b861e8d..a3c83ec416c6 100644
--- a/arch/powerpc/include/asm/hardirq.h
+++ b/arch/powerpc/include/asm/hardirq.h@@ -12,6 +12,10 @@ typedef struct { unsigned int mce_exceptions; unsigned int spurious_irqs; unsigned int hmi_exceptions; + unsigned int sreset_irqs; +#if defined(CONFIG_HARDLOCKUP_DETECTOR) && defined(CONFIG_HAVE_HARDLOCKUP_DETECTOR_ARCH) + unsigned int soft_nmi_irqs; +#endif #ifdef CONFIG_PPC_DOORBELL unsigned int doorbell_irqs; #endif
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 0bcec745a672..36250df64615 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c@@ -470,6 +470,18 @@ int arch_show_interrupts(struct seq_file *p, int prec) seq_printf(p, " Hypervisor Maintenance Interrupts\n"); } + seq_printf(p, "%*s: ", prec, "NMI"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", per_cpu(irq_stat, j).sreset_irqs); + seq_printf(p, " System Reset interrupts\n"); + +#if defined(CONFIG_HARDLOCKUP_DETECTOR) && defined(CONFIG_HAVE_HARDLOCKUP_DETECTOR_ARCH) + seq_printf(p, "%*s: ", prec, "WDG"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", per_cpu(irq_stat, j).soft_nmi_irqs); + seq_printf(p, " Watchdog soft-NMI interrupts\n"); +#endif + #ifdef CONFIG_PPC_DOORBELL if (cpu_has_feature(CPU_FTR_DBELL)) { seq_printf(p, "%*s: ", prec, "DBL");
@@ -494,6 +506,10 @@ u64 arch_irq_stat_cpu(unsigned int cpu) sum += per_cpu(irq_stat, cpu).spurious_irqs; sum += per_cpu(irq_stat, cpu).timer_irqs_others; sum += per_cpu(irq_stat, cpu).hmi_exceptions; + sum += per_cpu(irq_stat, cpu).sreset_irqs; +#ifdef CONFIG_HARDLOCKUP_DETECTOR + sum += per_cpu(irq_stat, cpu).soft_nmi_irqs; +#endif #ifdef CONFIG_PPC_DOORBELL sum += per_cpu(irq_stat, cpu).doorbell_irqs; #endif
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index bfcfd9ef09f2..6a892ca7bf18 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c@@ -288,6 +288,8 @@ void system_reset_exception(struct pt_regs *regs) if (!nested) nmi_enter(); + __this_cpu_inc(irq_stat.sreset_irqs); + /* See if any machine dependent calls */ if (ppc_md.system_reset_exception) { if (ppc_md.system_reset_exception(regs))
@@ -755,7 +757,14 @@ void machine_check_exception(struct pt_regs *regs) enum ctx_state prev_state = exception_enter(); int recover = 0; +#ifdef CONFIG_PPC_BOOK3S_64 + /* 64s accounts the mce in machine_check_early when in HVMODE */ + if (!cpu_has_feature(CPU_FTR_HVMODE)) + __this_cpu_inc(irq_stat.mce_exceptions); +#else __this_cpu_inc(irq_stat.mce_exceptions); +#endif + add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c
index b67f8b03a32d..4b9a567c9975 100644
--- a/arch/powerpc/kernel/watchdog.c
+++ b/arch/powerpc/kernel/watchdog.c@@ -204,6 +204,9 @@ void soft_nmi_interrupt(struct pt_regs *regs) return; nmi_enter(); + + __this_cpu_inc(irq_stat.soft_nmi_irqs); + tb = get_tb(); if (tb - per_cpu(wd_timer_tb, cpu) >= wd_panic_timeout_tb) { per_cpu(wd_timer_tb, cpu) = tb;
--
2.11.0