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authorRobert Richter <robert.richter@amd.com>2010-05-03 14:41:22 +0200
committerRobert Richter <robert.richter@amd.com>2010-05-04 11:39:38 +0200
commitde654649737696ecf32873c341b305e30f3dc777 (patch)
tree242e9a9f7d03b4da10b9786c895f46a8451a1725 /arch/x86/oprofile/nmi_int.c
parent6ae56b55bc364bc2f2342f599b46581627ba22da (diff)
downloadlinux-2.6.38-lt-ux500-de654649737696ecf32873c341b305e30f3dc777.tar.gz
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 <andi@firstfloor.org> Signed-off-by: Robert Richter <robert.richter@amd.com>
Diffstat (limited to 'arch/x86/oprofile/nmi_int.c')
-rw-r--r--arch/x86/oprofile/nmi_int.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index b56601eaf29..94b5481bb6c 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);