From de654649737696ecf32873c341b305e30f3dc777 Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Mon, 3 May 2010 14:41:22 +0200 Subject: [PATCH] oprofile/x86: stop disabled counters in nmi handler This patch adds checks to the nmi handler. Now samples are only generated and counters reenabled, if the counters are running. Otherwise the counters are stopped, if oprofile is using the nmi. In other cases it will ignore the nmi notification. Cc: Andi Kleen Signed-off-by: Robert Richter --- arch/x86/oprofile/nmi_int.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c index b56601e..94b5481 100644 --- a/arch/x86/oprofile/nmi_int.c +++ b/arch/x86/oprofile/nmi_int.c @@ -62,12 +62,16 @@ static int profile_exceptions_notify(struct notifier_block *self, { struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; - int cpu = smp_processor_id(); switch (val) { case DIE_NMI: case DIE_NMI_IPI: - model->check_ctrs(args->regs, &per_cpu(cpu_msrs, cpu)); + if (ctr_running) + model->check_ctrs(args->regs, &__get_cpu_var(cpu_msrs)); + else if (!nmi_enabled) + break; + else + model->stop(&__get_cpu_var(cpu_msrs)); ret = NOTIFY_STOP; break; default: @@ -392,6 +396,9 @@ static int nmi_setup(void) mux_clone(cpu); } + nmi_enabled = 0; + ctr_running = 0; + barrier(); err = register_die_notifier(&profile_exceptions_nb); if (err) goto fail; @@ -451,6 +458,7 @@ static void nmi_shutdown(void) nmi_enabled = 0; ctr_running = 0; put_online_cpus(); + barrier(); unregister_die_notifier(&profile_exceptions_nb); msrs = &get_cpu_var(cpu_msrs); model->shutdown(msrs); -- 2.7.4