Re: [Intel-gfx] [RFC v5 05/11] drm/i915/pmu: Suspend sampling when GPU is idle
On 14/09/2017 20:57, Chris Wilson wrote: Quoting Tvrtko Ursulin (2017-09-13 11:34:17) From: Tvrtko Ursulin If only a subset of events is enabled we can afford to suspend the sampling timer when the GPU is idle and so save some cycles and power. v2: Rebase and limit timer even more. v3: Rebase. v4: Rebase. v5: Skip action if perf PMU failed to register. Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_drv.h | 8 drivers/gpu/drm/i915/i915_gem.c | 1 + drivers/gpu/drm/i915/i915_gem_request.c | 1 + drivers/gpu/drm/i915/i915_pmu.c | 70 - 4 files changed, 70 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 62646b8dfb7a..70be8c5d9a65 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2244,6 +2244,10 @@ struct i915_pmu { */ unsigned int enable_count[I915_PMU_MASK_BITS]; /** +* @timer_enabled: Should the internal sampling timer be running. +*/ + bool timer_enabled; + /** * @sample: Current counter value for i915 events which need sampling. * * These counters are updated from the i915 PMU sampling timer. @@ -3989,9 +3993,13 @@ extern void i915_perf_unregister(struct drm_i915_private *dev_priv); #ifdef CONFIG_PERF_EVENTS extern void i915_pmu_register(struct drm_i915_private *i915); extern void i915_pmu_unregister(struct drm_i915_private *i915); +extern void i915_pmu_gt_idle(struct drm_i915_private *i915); +extern void i915_pmu_gt_active(struct drm_i915_private *i915); #else static inline void i915_pmu_register(struct drm_i915_private *i915) {} static inline void i915_pmu_unregister(struct drm_i915_private *i915) {} +static inline void i915_pmu_gt_idle(struct drm_i915_private *i915) {} +static inline void i915_pmu_gt_active(struct drm_i915_private *i915) {} #endif /* i915_suspend.c */ diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index f445587c1a4b..201b09eda93b 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3227,6 +3227,7 @@ i915_gem_idle_work_handler(struct work_struct *work) intel_engines_mark_idle(dev_priv); i915_gem_timelines_mark_idle(dev_priv); + i915_pmu_gt_idle(dev_priv); GEM_BUG_ON(!dev_priv->gt.awake); dev_priv->gt.awake = false; diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c index 813a3b546d6e..18a1e379253e 100644 --- a/drivers/gpu/drm/i915/i915_gem_request.c +++ b/drivers/gpu/drm/i915/i915_gem_request.c @@ -258,6 +258,7 @@ static void mark_busy(struct drm_i915_private *i915) i915_update_gfx_val(i915); if (INTEL_GEN(i915) >= 6) gen6_rps_busy(i915); + i915_pmu_gt_active(i915); queue_delayed_work(i915->wq, &i915->gt.retire_work, diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c index e82648e6635b..22246918757c 100644 --- a/drivers/gpu/drm/i915/i915_pmu.c +++ b/drivers/gpu/drm/i915/i915_pmu.c @@ -90,6 +90,52 @@ static unsigned int event_enabled_bit(struct perf_event *event) return config_enabled_bit(event->attr.config); } +static bool pmu_needs_timer(struct drm_i915_private *i915, bool gpu_active) +{ + u64 enable = i915->pmu.enable; + + enable &= config_enabled_mask(I915_PMU_ACTUAL_FREQUENCY) | + config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY) | + ENGINE_SAMPLE_MASK; + + if (!gpu_active) + enable &= ~ENGINE_SAMPLE_MASK; Ok. I'll add a comment here. It gets even more advanced when busy stats are added. + + return enable; +} + +void i915_pmu_gt_idle(struct drm_i915_private *i915) +{ + if (!i915->pmu.base.event_init) + return; + + spin_lock_irq(&i915->pmu.lock); + /* +* Signal sampling timer to stop if only engine events are enabled and +* GPU went idle. +*/ + i915->pmu.timer_enabled = pmu_needs_timer(i915, false); + spin_unlock_irq(&i915->pmu.lock); +} + +void i915_pmu_gt_active(struct drm_i915_private *i915) +{ + if (!i915->pmu.base.event_init) + return; + + spin_lock_irq(&i915->pmu.lock); + /* +* Re-enable sampling timer when GPU goes active. +*/ + if (!i915->pmu.timer_enabled && pmu_needs_timer(i915, true)) { + i915->pmu.timer_enabled = true; + hrtimer_start_range_ns(&i915->pmu.timer, + ns_to_ktime(PERIOD), 0, + HRTIMER_MODE_REL_PINNED); + } Duplication here, __i915_pmu_gt_active() for the critical section. Then also helps allay fears that we hold the spinlock which is not clear from the diff context below. Ag
Re: [Intel-gfx] [RFC v5 05/11] drm/i915/pmu: Suspend sampling when GPU is idle
Quoting Tvrtko Ursulin (2017-09-13 11:34:17) > From: Tvrtko Ursulin > > If only a subset of events is enabled we can afford to suspend > the sampling timer when the GPU is idle and so save some cycles > and power. > > v2: Rebase and limit timer even more. > v3: Rebase. > v4: Rebase. > v5: Skip action if perf PMU failed to register. > > Signed-off-by: Tvrtko Ursulin > --- > drivers/gpu/drm/i915/i915_drv.h | 8 > drivers/gpu/drm/i915/i915_gem.c | 1 + > drivers/gpu/drm/i915/i915_gem_request.c | 1 + > drivers/gpu/drm/i915/i915_pmu.c | 70 > - > 4 files changed, 70 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 62646b8dfb7a..70be8c5d9a65 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -2244,6 +2244,10 @@ struct i915_pmu { > */ > unsigned int enable_count[I915_PMU_MASK_BITS]; > /** > +* @timer_enabled: Should the internal sampling timer be running. > +*/ > + bool timer_enabled; > + /** > * @sample: Current counter value for i915 events which need sampling. > * > * These counters are updated from the i915 PMU sampling timer. > @@ -3989,9 +3993,13 @@ extern void i915_perf_unregister(struct > drm_i915_private *dev_priv); > #ifdef CONFIG_PERF_EVENTS > extern void i915_pmu_register(struct drm_i915_private *i915); > extern void i915_pmu_unregister(struct drm_i915_private *i915); > +extern void i915_pmu_gt_idle(struct drm_i915_private *i915); > +extern void i915_pmu_gt_active(struct drm_i915_private *i915); > #else > static inline void i915_pmu_register(struct drm_i915_private *i915) {} > static inline void i915_pmu_unregister(struct drm_i915_private *i915) {} > +static inline void i915_pmu_gt_idle(struct drm_i915_private *i915) {} > +static inline void i915_pmu_gt_active(struct drm_i915_private *i915) {} > #endif > > /* i915_suspend.c */ > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index f445587c1a4b..201b09eda93b 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -3227,6 +3227,7 @@ i915_gem_idle_work_handler(struct work_struct *work) > > intel_engines_mark_idle(dev_priv); > i915_gem_timelines_mark_idle(dev_priv); > + i915_pmu_gt_idle(dev_priv); > > GEM_BUG_ON(!dev_priv->gt.awake); > dev_priv->gt.awake = false; > diff --git a/drivers/gpu/drm/i915/i915_gem_request.c > b/drivers/gpu/drm/i915/i915_gem_request.c > index 813a3b546d6e..18a1e379253e 100644 > --- a/drivers/gpu/drm/i915/i915_gem_request.c > +++ b/drivers/gpu/drm/i915/i915_gem_request.c > @@ -258,6 +258,7 @@ static void mark_busy(struct drm_i915_private *i915) > i915_update_gfx_val(i915); > if (INTEL_GEN(i915) >= 6) > gen6_rps_busy(i915); > + i915_pmu_gt_active(i915); > > queue_delayed_work(i915->wq, >&i915->gt.retire_work, > diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c > index e82648e6635b..22246918757c 100644 > --- a/drivers/gpu/drm/i915/i915_pmu.c > +++ b/drivers/gpu/drm/i915/i915_pmu.c > @@ -90,6 +90,52 @@ static unsigned int event_enabled_bit(struct perf_event > *event) > return config_enabled_bit(event->attr.config); > } > > +static bool pmu_needs_timer(struct drm_i915_private *i915, bool gpu_active) > +{ > + u64 enable = i915->pmu.enable; > + > + enable &= config_enabled_mask(I915_PMU_ACTUAL_FREQUENCY) | > + config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY) | > + ENGINE_SAMPLE_MASK; > + > + if (!gpu_active) > + enable &= ~ENGINE_SAMPLE_MASK; Ok. > + > + return enable; > +} > + > +void i915_pmu_gt_idle(struct drm_i915_private *i915) > +{ > + if (!i915->pmu.base.event_init) > + return; > + > + spin_lock_irq(&i915->pmu.lock); > + /* > +* Signal sampling timer to stop if only engine events are enabled and > +* GPU went idle. > +*/ > + i915->pmu.timer_enabled = pmu_needs_timer(i915, false); > + spin_unlock_irq(&i915->pmu.lock); > +} > + > +void i915_pmu_gt_active(struct drm_i915_private *i915) > +{ > + if (!i915->pmu.base.event_init) > + return; > + > + spin_lock_irq(&i915->pmu.lock); > + /* > +* Re-enable sampling timer when GPU goes active. > +*/ > + if (!i915->pmu.timer_enabled && pmu_needs_timer(i915, true)) { > + i915->pmu.timer_enabled = true; > + hrtimer_start_range_ns(&i915->pmu.timer, > + ns_to_ktime(PERIOD), 0, > + HRTIMER_MODE_REL_PINNED); > + } Duplication here, __i915_pmu_gt_active() for the critical section. Then also helps allay
[Intel-gfx] [RFC v5 05/11] drm/i915/pmu: Suspend sampling when GPU is idle
From: Tvrtko Ursulin If only a subset of events is enabled we can afford to suspend the sampling timer when the GPU is idle and so save some cycles and power. v2: Rebase and limit timer even more. v3: Rebase. v4: Rebase. v5: Skip action if perf PMU failed to register. Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_drv.h | 8 drivers/gpu/drm/i915/i915_gem.c | 1 + drivers/gpu/drm/i915/i915_gem_request.c | 1 + drivers/gpu/drm/i915/i915_pmu.c | 70 - 4 files changed, 70 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 62646b8dfb7a..70be8c5d9a65 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2244,6 +2244,10 @@ struct i915_pmu { */ unsigned int enable_count[I915_PMU_MASK_BITS]; /** +* @timer_enabled: Should the internal sampling timer be running. +*/ + bool timer_enabled; + /** * @sample: Current counter value for i915 events which need sampling. * * These counters are updated from the i915 PMU sampling timer. @@ -3989,9 +3993,13 @@ extern void i915_perf_unregister(struct drm_i915_private *dev_priv); #ifdef CONFIG_PERF_EVENTS extern void i915_pmu_register(struct drm_i915_private *i915); extern void i915_pmu_unregister(struct drm_i915_private *i915); +extern void i915_pmu_gt_idle(struct drm_i915_private *i915); +extern void i915_pmu_gt_active(struct drm_i915_private *i915); #else static inline void i915_pmu_register(struct drm_i915_private *i915) {} static inline void i915_pmu_unregister(struct drm_i915_private *i915) {} +static inline void i915_pmu_gt_idle(struct drm_i915_private *i915) {} +static inline void i915_pmu_gt_active(struct drm_i915_private *i915) {} #endif /* i915_suspend.c */ diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index f445587c1a4b..201b09eda93b 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3227,6 +3227,7 @@ i915_gem_idle_work_handler(struct work_struct *work) intel_engines_mark_idle(dev_priv); i915_gem_timelines_mark_idle(dev_priv); + i915_pmu_gt_idle(dev_priv); GEM_BUG_ON(!dev_priv->gt.awake); dev_priv->gt.awake = false; diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c index 813a3b546d6e..18a1e379253e 100644 --- a/drivers/gpu/drm/i915/i915_gem_request.c +++ b/drivers/gpu/drm/i915/i915_gem_request.c @@ -258,6 +258,7 @@ static void mark_busy(struct drm_i915_private *i915) i915_update_gfx_val(i915); if (INTEL_GEN(i915) >= 6) gen6_rps_busy(i915); + i915_pmu_gt_active(i915); queue_delayed_work(i915->wq, &i915->gt.retire_work, diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c index e82648e6635b..22246918757c 100644 --- a/drivers/gpu/drm/i915/i915_pmu.c +++ b/drivers/gpu/drm/i915/i915_pmu.c @@ -90,6 +90,52 @@ static unsigned int event_enabled_bit(struct perf_event *event) return config_enabled_bit(event->attr.config); } +static bool pmu_needs_timer(struct drm_i915_private *i915, bool gpu_active) +{ + u64 enable = i915->pmu.enable; + + enable &= config_enabled_mask(I915_PMU_ACTUAL_FREQUENCY) | + config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY) | + ENGINE_SAMPLE_MASK; + + if (!gpu_active) + enable &= ~ENGINE_SAMPLE_MASK; + + return enable; +} + +void i915_pmu_gt_idle(struct drm_i915_private *i915) +{ + if (!i915->pmu.base.event_init) + return; + + spin_lock_irq(&i915->pmu.lock); + /* +* Signal sampling timer to stop if only engine events are enabled and +* GPU went idle. +*/ + i915->pmu.timer_enabled = pmu_needs_timer(i915, false); + spin_unlock_irq(&i915->pmu.lock); +} + +void i915_pmu_gt_active(struct drm_i915_private *i915) +{ + if (!i915->pmu.base.event_init) + return; + + spin_lock_irq(&i915->pmu.lock); + /* +* Re-enable sampling timer when GPU goes active. +*/ + if (!i915->pmu.timer_enabled && pmu_needs_timer(i915, true)) { + i915->pmu.timer_enabled = true; + hrtimer_start_range_ns(&i915->pmu.timer, + ns_to_ktime(PERIOD), 0, + HRTIMER_MODE_REL_PINNED); + } + spin_unlock_irq(&i915->pmu.lock); +} + static bool grab_forcewake(struct drm_i915_private *i915, bool fw) { if (!fw) @@ -180,7 +226,7 @@ static enum hrtimer_restart i915_sample(struct hrtimer *hrtimer) struct drm_i915_private *i915 = container_of(hrtimer, struct drm_i915_private, pmu.timer); - if (i915->pmu.enable == 0) + if (!READ_ONCE(