[PATCH 3/3] perf,x86: use common PMU interrupt disabled code

From: Vince Weaver
Date: Fri May 16 2014 - 17:14:16 EST



Make the x86 perf code use the new common PMU interrupt disabled code.

Typically most x86 machines have working PMU interrupts, although
some older p6-class machines had this problem.

Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx>

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index ae407f7..adba966 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)
@@ -1365,6 +1356,15 @@ 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_NO_INTERRUPT;
+
}

static struct attribute_group x86_pmu_format_group = {
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/