From: Chris Wilson Date: Wed, 29 Apr 2020 20:54:41 +0000 (+0100) Subject: drm/i915/gt: Always enable busy-stats for execlists X-Git-Tag: baikal/mips/sdk5.9~13559^2~12^2~8 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=a156d1d0a3a2ccc72ec3f41643aae83ebe6bbc6b;p=kernel.git drm/i915/gt: Always enable busy-stats for execlists In the near future, we will utilize the busy-stats on each engine to approximate the C0 cycles of each, and use that as an input to a manual RPS mechanism. That entails having busy-stats always enabled and so we can remove the enable/disable routines and simplify the pmu setup. As a consequence of always having the stats enabled, we can also show the current active time via sysfs/engine/xcs/active_time_ns. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20200429205446.3259-1-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h index d9ee64e2ef79e..d10e52ff059f4 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine.h +++ b/drivers/gpu/drm/i915/gt/intel_engine.h @@ -310,9 +310,6 @@ void intel_engine_dump(struct intel_engine_cs *engine, struct drm_printer *m, const char *header, ...); -int intel_enable_engine_stats(struct intel_engine_cs *engine); -void intel_disable_engine_stats(struct intel_engine_cs *engine); - ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine); struct i915_request * diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c index 80bf71636c0f4..c9e46c5ced43f 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c @@ -1589,58 +1589,6 @@ void intel_engine_dump(struct intel_engine_cs *engine, intel_engine_print_breadcrumbs(engine, m); } -/** - * intel_enable_engine_stats() - Enable engine busy tracking on engine - * @engine: engine to enable stats collection - * - * Start collecting the engine busyness data for @engine. - * - * Returns 0 on success or a negative error code. - */ -int intel_enable_engine_stats(struct intel_engine_cs *engine) -{ - struct intel_engine_execlists *execlists = &engine->execlists; - unsigned long flags; - int err = 0; - - if (!intel_engine_supports_stats(engine)) - return -ENODEV; - - execlists_active_lock_bh(execlists); - write_seqlock_irqsave(&engine->stats.lock, flags); - - if (unlikely(engine->stats.enabled == ~0)) { - err = -EBUSY; - goto unlock; - } - - if (engine->stats.enabled++ == 0) { - struct i915_request * const *port; - struct i915_request *rq; - - engine->stats.enabled_at = ktime_get(); - - /* XXX submission method oblivious? */ - for (port = execlists->active; (rq = *port); port++) - engine->stats.active++; - - for (port = execlists->pending; (rq = *port); port++) { - /* Exclude any contexts already counted in active */ - if (!intel_context_inflight_count(rq->context)) - engine->stats.active++; - } - - if (engine->stats.active) - engine->stats.start = engine->stats.enabled_at; - } - -unlock: - write_sequnlock_irqrestore(&engine->stats.lock, flags); - execlists_active_unlock_bh(execlists); - - return err; -} - static ktime_t __intel_engine_get_busy_time(struct intel_engine_cs *engine) { ktime_t total = engine->stats.total; @@ -1649,7 +1597,7 @@ static ktime_t __intel_engine_get_busy_time(struct intel_engine_cs *engine) * If the engine is executing something at the moment * add it to the total. */ - if (engine->stats.active) + if (atomic_read(&engine->stats.active)) total = ktime_add(total, ktime_sub(ktime_get(), engine->stats.start)); @@ -1675,28 +1623,6 @@ ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine) return total; } -/** - * intel_disable_engine_stats() - Disable engine busy tracking on engine - * @engine: engine to disable stats collection - * - * Stops collecting the engine busyness data for @engine. - */ -void intel_disable_engine_stats(struct intel_engine_cs *engine) -{ - unsigned long flags; - - if (!intel_engine_supports_stats(engine)) - return; - - write_seqlock_irqsave(&engine->stats.lock, flags); - WARN_ON_ONCE(engine->stats.enabled == 0); - if (--engine->stats.enabled == 0) { - engine->stats.total = __intel_engine_get_busy_time(engine); - engine->stats.active = 0; - } - write_sequnlock_irqrestore(&engine->stats.lock, flags); -} - static bool match_ring(struct i915_request *rq) { u32 ring = ENGINE_READ(rq->engine, RING_START); diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h index 483d8ff39a0d2..83b1f95ebf12e 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h @@ -531,28 +531,16 @@ struct intel_engine_cs { u32 (*get_cmd_length_mask)(u32 cmd_header); struct { - /** - * @lock: Lock protecting the below fields. - */ - seqlock_t lock; - /** - * @enabled: Reference count indicating number of listeners. - */ - unsigned int enabled; /** * @active: Number of contexts currently scheduled in. */ - unsigned int active; - /** - * @enabled_at: Timestamp when busy stats were enabled. - */ - ktime_t enabled_at; + atomic_t active; + /** - * @start: Timestamp of the last idle to active transition. - * - * Idle is defined as active == 0, active is active > 0. + * @lock: Lock protecting the below fields. */ - ktime_t start; + seqlock_t lock; + /** * @total: Total time this engine was busy. * @@ -560,6 +548,13 @@ struct intel_engine_cs { * where engine is currently busy (active > 0). */ ktime_t total; + + /** + * @start: Timestamp of the last idle to active transition. + * + * Idle is defined as active == 0, active is active > 0. + */ + ktime_t start; } stats; struct { diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 7fc4081c34feb..4311b12542fbb 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -1199,17 +1199,14 @@ static void intel_engine_context_in(struct intel_engine_cs *engine) { unsigned long flags; - if (READ_ONCE(engine->stats.enabled) == 0) + if (atomic_add_unless(&engine->stats.active, 1, 0)) return; write_seqlock_irqsave(&engine->stats.lock, flags); - - if (engine->stats.enabled > 0) { - if (engine->stats.active++ == 0) - engine->stats.start = ktime_get(); - GEM_BUG_ON(engine->stats.active == 0); + if (!atomic_add_unless(&engine->stats.active, 1, 0)) { + engine->stats.start = ktime_get(); + atomic_inc(&engine->stats.active); } - write_sequnlock_irqrestore(&engine->stats.lock, flags); } @@ -1217,36 +1214,17 @@ static void intel_engine_context_out(struct intel_engine_cs *engine) { unsigned long flags; - if (READ_ONCE(engine->stats.enabled) == 0) + GEM_BUG_ON(!atomic_read(&engine->stats.active)); + + if (atomic_add_unless(&engine->stats.active, -1, 1)) return; write_seqlock_irqsave(&engine->stats.lock, flags); - - if (engine->stats.enabled > 0) { - ktime_t last; - - if (engine->stats.active && --engine->stats.active == 0) { - /* - * Decrement the active context count and in case GPU - * is now idle add up to the running total. - */ - last = ktime_sub(ktime_get(), engine->stats.start); - - engine->stats.total = ktime_add(engine->stats.total, - last); - } else if (engine->stats.active == 0) { - /* - * After turning on engine stats, context out might be - * the first event in which case we account from the - * time stats gathering was turned on. - */ - last = ktime_sub(ktime_get(), engine->stats.enabled_at); - - engine->stats.total = ktime_add(engine->stats.total, - last); - } + if (atomic_dec_and_test(&engine->stats.active)) { + engine->stats.total = + ktime_add(engine->stats.total, + ktime_sub(ktime_get(), engine->stats.start)); } - write_sequnlock_irqrestore(&engine->stats.lock, flags); } diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c index 230e9256ab308..83c6a8ccd2cb2 100644 --- a/drivers/gpu/drm/i915/i915_pmu.c +++ b/drivers/gpu/drm/i915/i915_pmu.c @@ -439,29 +439,9 @@ static u64 count_interrupts(struct drm_i915_private *i915) return sum; } -static void engine_event_destroy(struct perf_event *event) -{ - struct drm_i915_private *i915 = - container_of(event->pmu, typeof(*i915), pmu.base); - struct intel_engine_cs *engine; - - engine = intel_engine_lookup_user(i915, - engine_event_class(event), - engine_event_instance(event)); - if (drm_WARN_ON_ONCE(&i915->drm, !engine)) - return; - - if (engine_event_sample(event) == I915_SAMPLE_BUSY && - intel_engine_supports_stats(engine)) - intel_disable_engine_stats(engine); -} - static void i915_pmu_event_destroy(struct perf_event *event) { WARN_ON(event->parent); - - if (is_engine_event(event)) - engine_event_destroy(event); } static int @@ -514,23 +494,13 @@ static int engine_event_init(struct perf_event *event) struct drm_i915_private *i915 = container_of(event->pmu, typeof(*i915), pmu.base); struct intel_engine_cs *engine; - u8 sample; - int ret; engine = intel_engine_lookup_user(i915, engine_event_class(event), engine_event_instance(event)); if (!engine) return -ENODEV; - sample = engine_event_sample(event); - ret = engine_event_status(engine, sample); - if (ret) - return ret; - - if (sample == I915_SAMPLE_BUSY && intel_engine_supports_stats(engine)) - ret = intel_enable_engine_stats(engine); - - return ret; + return engine_event_status(engine, engine_event_sample(event)); } static int i915_pmu_event_init(struct perf_event *event) diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c index 3b319c0953cba..15b1ca9f7a01c 100644 --- a/drivers/gpu/drm/i915/selftests/i915_request.c +++ b/drivers/gpu/drm/i915/selftests/i915_request.c @@ -1679,8 +1679,7 @@ static int perf_series_engines(void *arg) p->engine = ps->ce[idx]->engine; intel_engine_pm_get(p->engine); - if (intel_engine_supports_stats(p->engine) && - !intel_enable_engine_stats(p->engine)) + if (intel_engine_supports_stats(p->engine)) p->busy = intel_engine_get_busy_time(p->engine) + 1; p->runtime = -intel_context_get_total_runtime_ns(ce); p->time = ktime_get(); @@ -1700,7 +1699,6 @@ static int perf_series_engines(void *arg) if (p->busy) { p->busy = ktime_sub(intel_engine_get_busy_time(p->engine), p->busy - 1); - intel_disable_engine_stats(p->engine); } err = switch_to_kernel_sync(ce, err); @@ -1762,8 +1760,7 @@ static int p_sync0(void *arg) } busy = false; - if (intel_engine_supports_stats(engine) && - !intel_enable_engine_stats(engine)) { + if (intel_engine_supports_stats(engine)) { p->busy = intel_engine_get_busy_time(engine); busy = true; } @@ -1796,7 +1793,6 @@ static int p_sync0(void *arg) if (busy) { p->busy = ktime_sub(intel_engine_get_busy_time(engine), p->busy); - intel_disable_engine_stats(engine); } err = switch_to_kernel_sync(ce, err); @@ -1830,8 +1826,7 @@ static int p_sync1(void *arg) } busy = false; - if (intel_engine_supports_stats(engine) && - !intel_enable_engine_stats(engine)) { + if (intel_engine_supports_stats(engine)) { p->busy = intel_engine_get_busy_time(engine); busy = true; } @@ -1866,7 +1861,6 @@ static int p_sync1(void *arg) if (busy) { p->busy = ktime_sub(intel_engine_get_busy_time(engine), p->busy); - intel_disable_engine_stats(engine); } err = switch_to_kernel_sync(ce, err); @@ -1899,8 +1893,7 @@ static int p_many(void *arg) } busy = false; - if (intel_engine_supports_stats(engine) && - !intel_enable_engine_stats(engine)) { + if (intel_engine_supports_stats(engine)) { p->busy = intel_engine_get_busy_time(engine); busy = true; } @@ -1924,7 +1917,6 @@ static int p_many(void *arg) if (busy) { p->busy = ktime_sub(intel_engine_get_busy_time(engine), p->busy); - intel_disable_engine_stats(engine); } err = switch_to_kernel_sync(ce, err);