perf/x86/uncore: Fix event group support (75be6f70) · Commits · 戴 / test

The events in the same group don't start or stop simultaneously. Here is the ftrace when enabling event group for uncore_iio_0: # perf stat -e "{uncore_iio_0/event=0x1/,uncore_iio_0/event=0xe/}" <idle>-0 [000] d.h. 8959.064832: read_msr: a41, value b2b0b030 //Read counter reg of IIO unit0 counter0 <idle>-0 [000] d.h. 8959.064835: write_msr: a48, value 400001 //Write Ctrl reg of IIO unit0 counter0 to enable counter0. <------ Although counter0 is enabled, Unit Ctrl is still freezed. Nothing will count. We are still good here. <idle>-0 [000] d.h. 8959.064836: read_msr: a40, value 30100 //Read Unit Ctrl reg of IIO unit0 <idle>-0 [000] d.h. 8959.064838: write_msr: a40, value 30000 //Write Unit Ctrl reg of IIO unit0 to enable all counters in the unit by clear Freeze bit <------Unit0 is un-freezed. Counter0 has been enabled. Now it starts counting. But counter1 has not been enabled yet. The issue starts here. <idle>-0 [000] d.h. 8959.064846: read_msr: a42, value 0 //Read counter reg of IIO unit0 counter1 <idle>-0 [000] d.h. 8959.064847: write_msr: a49, value 40000e //Write Ctrl reg of IIO unit0 counter1 to enable counter1. <------ Now, counter1 just starts to count. Counter0 has been running for a while. Current code un-freezes the Unit Ctrl right after the first counter is enabled. The subsequent group events always loses some counter values. Implement pmu_enable and pmu_disable support for uncore, which can help to batch hardware accesses. No one uses uncore_enable_box and uncore_disable_box. Remove them. Signed-off-by:

Kan Liang <kan.liang@linux.intel.com> Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: linux-drivers-review@eclists.intel.com Cc: linux-perf@eclists.intel.com Fixes: ("perf/x86: Add generic Intel uncore PMU support") Link: https://lkml.kernel.org/r/1572014593-31591-1-git-send-email-kan.liang@linux.intel.com Signed-off-by:

Ingo Molnar <mingo@kernel.org>

arch/x86/events/intel/uncore.c

+38 −6

Original line number	Diff line number	Diff line
		@@ -502,11 +502,9 @@ void uncore_pmu_event_start(struct perf_event *event, int flags)
		local64_set(&event->hw.prev_count, uncore_read_counter(box, event));
		uncore_enable_event(box, event);

		if (box->n_active == 1) {
		uncore_enable_box(box);
		if (box->n_active == 1)
		uncore_pmu_start_hrtimer(box);
		}
		}

		void uncore_pmu_event_stop(struct perf_event *event, int flags)
		{
		@@ -529,11 +527,9 @@ void uncore_pmu_event_stop(struct perf_event *event, int flags)
		WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
		hwc->state \|= PERF_HES_STOPPED;

		if (box->n_active == 0) {
		uncore_disable_box(box);
		if (box->n_active == 0)
		uncore_pmu_cancel_hrtimer(box);
		}
		}

		if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
		/*
		@@ -778,6 +774,40 @@ static int uncore_pmu_event_init(struct perf_event *event)
		return ret;
		}

		static void uncore_pmu_enable(struct pmu *pmu)
		{
		struct intel_uncore_pmu *uncore_pmu;
		struct intel_uncore_box *box;

		uncore_pmu = container_of(pmu, struct intel_uncore_pmu, pmu);
		if (!uncore_pmu)
		return;

		box = uncore_pmu_to_box(uncore_pmu, smp_processor_id());
		if (!box)
		return;

		if (uncore_pmu->type->ops->enable_box)
		uncore_pmu->type->ops->enable_box(box);
		}

		static void uncore_pmu_disable(struct pmu *pmu)
		{
		struct intel_uncore_pmu *uncore_pmu;
		struct intel_uncore_box *box;

		uncore_pmu = container_of(pmu, struct intel_uncore_pmu, pmu);
		if (!uncore_pmu)
		return;

		box = uncore_pmu_to_box(uncore_pmu, smp_processor_id());
		if (!box)
		return;

		if (uncore_pmu->type->ops->disable_box)
		uncore_pmu->type->ops->disable_box(box);
		}

		static ssize_t uncore_get_attr_cpumask(struct device *dev,
		struct device_attribute attr, char buf)
		{
		@@ -803,6 +833,8 @@ static int uncore_pmu_register(struct intel_uncore_pmu *pmu)
		pmu->pmu = (struct pmu) {
		.attr_groups = pmu->type->attr_groups,
		.task_ctx_nr = perf_invalid_context,
		.pmu_enable = uncore_pmu_enable,
		.pmu_disable = uncore_pmu_disable,
		.event_init = uncore_pmu_event_init,
		.add = uncore_pmu_event_add,
		.del = uncore_pmu_event_del,

arch/x86/events/intel/uncore.h

+0 −12

Original line number	Diff line number	Diff line
		@@ -441,18 +441,6 @@ static inline int uncore_freerunning_hw_config(struct intel_uncore_box *box,
		return -EINVAL;
		}

		static inline void uncore_disable_box(struct intel_uncore_box *box)
		{
		if (box->pmu->type->ops->disable_box)
		box->pmu->type->ops->disable_box(box);
		}

		static inline void uncore_enable_box(struct intel_uncore_box *box)
		{
		if (box->pmu->type->ops->enable_box)
		box->pmu->type->ops->enable_box(box);
		}

		static inline void uncore_disable_event(struct intel_uncore_box *box,
		struct perf_event *event)
		{

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