drm/i915/pmu: Correct the rc6 offset upon enabling (88a9c66d) · Commits · 戴 / test

The rc6 residency starts ticking from 0 from BIOS POST, but the kernel starts measuring the time from its boot. If we start measuruing I915_PMU_RC6_RESIDENCY while the GT is idle, we start our sampling from 0 and then upon first activity (park/unpark) add in all the rc6 residency since boot. After the first park with the sampler engaged, the sleep/active counters are aligned. v2: With a wakeref to be sure Closes: https://gitlab.freedesktop.org/drm/intel/issues/973 Fixes: ("drm/i915/pmu: Ensure monotonic rc6") Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by:

Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200114105648.2172026-1-chris@chris-wilson.co.uk (cherry picked from commit ) Signed-off-by:

Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/i915_pmu.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -637,8 +637,10 @@ static void i915_pmu_enable(struct perf_event *event)
		container_of(event->pmu, typeof(*i915), pmu.base);
		unsigned int bit = event_enabled_bit(event);
		struct i915_pmu *pmu = &i915->pmu;
		intel_wakeref_t wakeref;
		unsigned long flags;

		wakeref = intel_runtime_pm_get(&i915->runtime_pm);
		spin_lock_irqsave(&pmu->lock, flags);

		/*
		@@ -648,6 +650,14 @@ static void i915_pmu_enable(struct perf_event *event)
		BUILD_BUG_ON(ARRAY_SIZE(pmu->enable_count) != I915_PMU_MASK_BITS);
		GEM_BUG_ON(bit >= ARRAY_SIZE(pmu->enable_count));
		GEM_BUG_ON(pmu->enable_count[bit] == ~0);

		if (pmu->enable_count[bit] == 0 &&
		config_enabled_mask(I915_PMU_RC6_RESIDENCY) & BIT_ULL(bit)) {
		pmu->sample[__I915_SAMPLE_RC6_LAST_REPORTED].cur = 0;
		pmu->sample[__I915_SAMPLE_RC6].cur = __get_rc6(&i915->gt);
		pmu->sleep_last = ktime_get();
		}

		pmu->enable \|= BIT_ULL(bit);
		pmu->enable_count[bit]++;

		@@ -688,6 +698,8 @@ static void i915_pmu_enable(struct perf_event *event)
		* an existing non-zero value.
		*/
		local64_set(&event->hw.prev_count, __i915_pmu_event_read(event));

		intel_runtime_pm_put(&i915->runtime_pm, wakeref);
		}

		static void i915_pmu_disable(struct perf_event *event)

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