From c6eeb4797eb94ad14bb34adfccbc6addad2cfd48 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 8 Mar 2019 09:36:56 +0000 Subject: drm/i915: Reduce presumption of request ordering for barriers Currently we assume that we know the order in which requests run and so can determine if we need to reissue a switch-to-kernel-context prior to idling. That assumption does not hold for the future, so instead of tracking which barriers have been used, simply determine if we have ever switched away from the kernel context by using the engine and before idling ensure that all engines that have been used since the last idle are synchronously switched back to the kernel context for safety (and else of shrinking memory while idle). v2: Use intel_engine_mask_t and ALL_ENGINES Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20190308093657.8640-3-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem_evict.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpu/drm/i915/i915_gem_evict.c') diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c index 68d74c50ac39..7d8e90dfca84 100644 --- a/drivers/gpu/drm/i915/i915_gem_evict.c +++ b/drivers/gpu/drm/i915/i915_gem_evict.c @@ -62,7 +62,7 @@ static int ggtt_flush(struct drm_i915_private *i915) * the hopes that we can then remove contexts and the like only * bound by their active reference. */ - err = i915_gem_switch_to_kernel_context(i915); + err = i915_gem_switch_to_kernel_context(i915, i915->gt.active_engines); if (err) return err; -- cgit v1.2.3 From 7d6ce55887a44c15c6df29e883d0ea567c8ac55c Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 8 Mar 2019 09:36:57 +0000 Subject: drm/i915: Remove has-kernel-context We can no longer assume execution ordering, and in particular we cannot assume which context will execute last. One side-effect of this is that we cannot determine if the kernel-context is resident on the GPU, so remove the routines that claimed to do so. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20190308093657.8640-4-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_active.h | 13 ------------- drivers/gpu/drm/i915/i915_gem.c | 21 +-------------------- drivers/gpu/drm/i915/i915_gem_evict.c | 16 +++------------- drivers/gpu/drm/i915/intel_engine_cs.c | 31 ------------------------------- drivers/gpu/drm/i915/intel_ringbuffer.h | 1 - 5 files changed, 4 insertions(+), 78 deletions(-) (limited to 'drivers/gpu/drm/i915/i915_gem_evict.c') diff --git a/drivers/gpu/drm/i915/i915_active.h b/drivers/gpu/drm/i915/i915_active.h index 8142a334b37b..7d758719ce39 100644 --- a/drivers/gpu/drm/i915/i915_active.h +++ b/drivers/gpu/drm/i915/i915_active.h @@ -108,19 +108,6 @@ i915_active_request_set_retire_fn(struct i915_active_request *active, active->retire = fn ?: i915_active_retire_noop; } -static inline struct i915_request * -__i915_active_request_peek(const struct i915_active_request *active) -{ - /* - * Inside the error capture (running with the driver in an unknown - * state), we want to bend the rules slightly (a lot). - * - * Work is in progress to make it safer, in the meantime this keeps - * the known issue from spamming the logs. - */ - return rcu_dereference_protected(active->request, 1); -} - /** * i915_active_request_raw - return the active request * @active - the active tracker diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 961237b90b40..1f1849f90606 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2828,23 +2828,6 @@ i915_gem_retire_work_handler(struct work_struct *work) round_jiffies_up_relative(HZ)); } -static void assert_kernel_context_is_current(struct drm_i915_private *i915) -{ - struct intel_engine_cs *engine; - enum intel_engine_id id; - - if (i915_reset_failed(i915)) - return; - - i915_retire_requests(i915); - - for_each_engine(engine, i915, id) { - GEM_BUG_ON(__i915_active_request_peek(&engine->timeline.last_request)); - GEM_BUG_ON(engine->last_retired_context != - to_intel_context(i915->kernel_context, engine)); - } -} - static bool switch_to_kernel_context_sync(struct drm_i915_private *i915, unsigned long mask) { @@ -2864,9 +2847,7 @@ static bool switch_to_kernel_context_sync(struct drm_i915_private *i915, I915_GEM_IDLE_TIMEOUT)) result = false; - if (result) { - assert_kernel_context_is_current(i915); - } else { + if (!result) { /* Forcibly cancel outstanding work and leave the gpu quiet. */ dev_err(i915->drm.dev, "Failed to idle engines, declaring wedged!\n"); diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c index 7d8e90dfca84..060f5903544a 100644 --- a/drivers/gpu/drm/i915/i915_gem_evict.c +++ b/drivers/gpu/drm/i915/i915_gem_evict.c @@ -38,25 +38,15 @@ I915_SELFTEST_DECLARE(static struct igt_evict_ctl { static bool ggtt_is_idle(struct drm_i915_private *i915) { - struct intel_engine_cs *engine; - enum intel_engine_id id; - - if (i915->gt.active_requests) - return false; - - for_each_engine(engine, i915, id) { - if (!intel_engine_has_kernel_context(engine)) - return false; - } - - return true; + return !i915->gt.active_requests; } static int ggtt_flush(struct drm_i915_private *i915) { int err; - /* Not everything in the GGTT is tracked via vma (otherwise we + /* + * Not everything in the GGTT is tracked via vma (otherwise we * could evict as required with minimal stalling) so we are forced * to idle the GPU and explicitly retire outstanding requests in * the hopes that we can then remove contexts and the like only diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c index 18174f808fd8..8e326556499e 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -1090,37 +1090,6 @@ bool intel_engines_are_idle(struct drm_i915_private *i915) return true; } -/** - * intel_engine_has_kernel_context: - * @engine: the engine - * - * Returns true if the last context to be executed on this engine, or has been - * executed if the engine is already idle, is the kernel context - * (#i915.kernel_context). - */ -bool intel_engine_has_kernel_context(const struct intel_engine_cs *engine) -{ - const struct intel_context *kernel_context = - to_intel_context(engine->i915->kernel_context, engine); - struct i915_request *rq; - - lockdep_assert_held(&engine->i915->drm.struct_mutex); - - if (!engine->context_size) - return true; - - /* - * Check the last context seen by the engine. If active, it will be - * the last request that remains in the timeline. When idle, it is - * the last executed context as tracked by retirement. - */ - rq = __i915_active_request_peek(&engine->timeline.last_request); - if (rq) - return rq->hw_context == kernel_context; - else - return engine->last_retired_context == kernel_context; -} - void intel_engines_reset_default_submission(struct drm_i915_private *i915) { struct intel_engine_cs *engine; diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 84b7047e2df5..9ccbe63d46e3 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -935,7 +935,6 @@ void intel_engines_sanitize(struct drm_i915_private *i915, bool force); bool intel_engine_is_idle(struct intel_engine_cs *engine); bool intel_engines_are_idle(struct drm_i915_private *dev_priv); -bool intel_engine_has_kernel_context(const struct intel_engine_cs *engine); void intel_engine_lost_context(struct intel_engine_cs *engine); void intel_engines_park(struct drm_i915_private *i915); -- cgit v1.2.3