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Diffstat (limited to 'arch/x86/kernel/cpu/perf_event.c')
-rw-r--r--arch/x86/kernel/cpu/perf_event.c21
1 files changed, 11 insertions, 10 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 89f3b7c1af20..2bdfbff8a4f6 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -303,15 +303,6 @@ int x86_setup_perfctr(struct perf_event *event)
hwc->sample_period = x86_pmu.max_period;
hwc->last_period = hwc->sample_period;
local64_set(&hwc->period_left, hwc->sample_period);
- } else {
- /*
- * If we have a PMU initialized but no APIC
- * interrupts, we cannot sample hardware
- * events (user-space has to fall back and
- * sample via a hrtimer based software event):
- */
- if (!x86_pmu.apic)
- return -EOPNOTSUPP;
}
if (attr->type == PERF_TYPE_RAW)
@@ -1293,7 +1284,7 @@ void perf_events_lapic_init(void)
apic_write(APIC_LVTPC, APIC_DM_NMI);
}
-static int __kprobes
+static int
perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
{
u64 start_clock;
@@ -1311,6 +1302,7 @@ perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
return ret;
}
+NOKPROBE_SYMBOL(perf_event_nmi_handler);
struct event_constraint emptyconstraint;
struct event_constraint unconstrained;
@@ -1366,6 +1358,15 @@ static void __init pmu_check_apic(void)
x86_pmu.apic = 0;
pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n");
pr_info("no hardware sampling interrupt available.\n");
+
+ /*
+ * If we have a PMU initialized but no APIC
+ * interrupts, we cannot sample hardware
+ * events (user-space has to fall back and
+ * sample via a hrtimer based software event):
+ */
+ pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
+
}
static struct attribute_group x86_pmu_format_group = {