[Intel-gfx] [RFC 07/10] drm/i915: Engine busy time tracking
Tvrtko Ursulin
tursulin at ursulin.net
Wed Aug 2 12:32:47 UTC 2017
From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Track total time requests have been executing on the hardware.
We add new kernel API to allow software tracking of time GPU
engines are spending executing requests.
Both per-engine and global API is added with the latter also
being exported for use by external users.
v2:
* Squashed with the internal API.
* Dropped static key.
* Made per-engine.
* Store time in monotonic ktime.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
drivers/gpu/drm/i915/intel_engine_cs.c | 103 ++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_lrc.c | 2 +
drivers/gpu/drm/i915/intel_ringbuffer.h | 61 +++++++++++++++++++
3 files changed, 166 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 14630612325b..e709f4edef90 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -232,6 +232,8 @@ intel_engine_setup(struct drm_i915_private *dev_priv,
/* Nothing to do here, execute in order of dependencies */
engine->schedule = NULL;
+ spin_lock_init(&engine->stats.lock);
+
ATOMIC_INIT_NOTIFIER_HEAD(&engine->context_status_notifier);
dev_priv->engine_class[info->class][info->instance] = engine;
@@ -1345,6 +1347,107 @@ void intel_engines_mark_idle(struct drm_i915_private *i915)
}
}
+int intel_enable_engine_stats(struct intel_engine_cs *engine)
+{
+ unsigned long flags;
+
+ if (!i915.enable_execlists)
+ return -ENODEV;
+
+ spin_lock_irqsave(&engine->stats.lock, flags);
+ if (engine->stats.enabled++ == 0) {
+ engine->stats.ref = 0;
+ engine->stats.start = engine->stats.total = 0;
+ } else if (engine->stats.enabled == ~0) {
+ goto busy;
+ }
+ spin_unlock_irqrestore(&engine->stats.lock, flags);
+
+ return 0;
+
+busy:
+ spin_unlock_irqrestore(&engine->stats.lock, flags);
+
+ return -EBUSY;
+}
+
+void intel_disable_engine_stats(struct intel_engine_cs *engine)
+{
+ unsigned long flags;
+
+ if (!i915.enable_execlists)
+ return;
+
+ spin_lock_irqsave(&engine->stats.lock, flags);
+ WARN_ON_ONCE(engine->stats.enabled == 0);
+ engine->stats.enabled--;
+ spin_unlock_irqrestore(&engine->stats.lock, flags);
+}
+
+int intel_enable_engines_stats(struct drm_i915_private *dev_priv)
+{
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ int ret = 0;
+
+ if (!i915.enable_execlists)
+ return -ENODEV;
+
+ for_each_engine(engine, dev_priv, id) {
+ ret = intel_enable_engine_stats(engine);
+ if (WARN_ON_ONCE(ret))
+ break;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(intel_enable_engines_stats);
+
+void intel_disable_engines_stats(struct drm_i915_private *dev_priv)
+{
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+
+ for_each_engine(engine, dev_priv, id)
+ intel_disable_engine_stats(engine);
+}
+EXPORT_SYMBOL(intel_disable_engines_stats);
+
+ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine)
+{
+ ktime_t total;
+ unsigned long flags;
+
+ spin_lock_irqsave(&engine->stats.lock, flags);
+
+ total = engine->stats.total;
+
+ /*
+ * If the engine is executing something at the moment
+ * add it to the total.
+ */
+ if (engine->stats.ref)
+ total = ktime_add(total,
+ ktime_sub(ktime_get(), engine->stats.start));
+
+ spin_unlock_irqrestore(&engine->stats.lock, flags);
+
+ return total;
+}
+
+ktime_t intel_engines_get_busy_time(struct drm_i915_private *dev_priv)
+{
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ ktime_t total = 0;
+
+ for_each_engine(engine, dev_priv, id)
+ total = ktime_add(total, intel_engine_get_busy_time(engine));
+
+ return total;
+}
+EXPORT_SYMBOL(intel_engines_get_busy_time);
+
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftests/mock_engine.c"
#endif
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 4c2cb07c39e2..5de2fdb86e61 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -310,12 +310,14 @@ execlists_context_status_change(struct drm_i915_gem_request *rq,
static inline void
execlists_context_schedule_in(struct drm_i915_gem_request *rq)
{
+ intel_engine_context_in(rq->engine);
execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN);
}
static inline void
execlists_context_schedule_out(struct drm_i915_gem_request *rq)
{
+ intel_engine_context_out(rq->engine);
execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT);
}
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 9fdf0cdf6220..68f50ec72be6 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -446,6 +446,14 @@ struct intel_engine_cs {
* certain bits to encode the command length in the header).
*/
u32 (*get_cmd_length_mask)(u32 cmd_header);
+
+ struct {
+ spinlock_t lock;
+ unsigned int enabled;
+ unsigned int ref;
+ ktime_t start; /* Timestamp of the last idle to active transition. */
+ ktime_t total; /* Total time engined was busy. */
+ } stats;
};
static inline unsigned int
@@ -743,4 +751,57 @@ void intel_engines_reset_default_submission(struct drm_i915_private *i915);
struct intel_engine_cs *
intel_engine_lookup_user(struct drm_i915_private *i915, u8 class, u8 instance);
+static inline void intel_engine_context_in(struct intel_engine_cs *engine)
+{
+ unsigned long flags;
+
+ if (READ_ONCE(engine->stats.enabled) == 0)
+ return;
+
+ spin_lock_irqsave(&engine->stats.lock, flags);
+
+ if (engine->stats.enabled > 0) {
+ if (engine->stats.ref++ == 0)
+ engine->stats.start = ktime_get();
+ GEM_BUG_ON(engine->stats.ref == 0);
+ }
+
+ spin_unlock_irqrestore(&engine->stats.lock, flags);
+}
+
+static inline void intel_engine_context_out(struct intel_engine_cs *engine)
+{
+ unsigned long flags;
+
+ if (READ_ONCE(engine->stats.enabled) == 0)
+ return;
+
+ spin_lock_irqsave(&engine->stats.lock, flags);
+
+ if (engine->stats.enabled > 0) {
+ /*
+ * After turning on engine stats, context out might be the
+ * first event which then needs to be ignored (ref == 0).
+ */
+ if (engine->stats.ref && --engine->stats.ref == 0) {
+ ktime_t last = ktime_sub(ktime_get(),
+ engine->stats.start);
+
+ engine->stats.total = ktime_add(engine->stats.total,
+ last);
+ }
+ }
+
+ spin_unlock_irqrestore(&engine->stats.lock, flags);
+}
+
+int intel_enable_engine_stats(struct intel_engine_cs *engine);
+void intel_disable_engine_stats(struct intel_engine_cs *engine);
+
+int intel_enable_engines_stats(struct drm_i915_private *dev_priv);
+void intel_disable_engines_stats(struct drm_i915_private *dev_priv);
+
+ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine);
+ktime_t intel_engines_get_busy_time(struct drm_i915_private *dev_priv);
+
#endif /* _INTEL_RINGBUFFER_H_ */
--
2.9.4
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