We don't want to busywait on the GPU if we have other work to do. If we give non-busywaiting workloads higher (initial) priority than workloads that require a busywait, we will prioritise work that is ready to run immediately.
Testcase: igt/gem_exec_schedule/semaphore Signed-off-by: Chris Wilson <[email protected]> --- drivers/gpu/drm/i915/i915_request.c | 8 +++++++- drivers/gpu/drm/i915/i915_scheduler.c | 2 +- drivers/gpu/drm/i915/i915_scheduler.h | 11 +++++++---- drivers/gpu/drm/i915/intel_lrc.c | 5 +++-- 4 files changed, 18 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 6d825cd28ae6..30cd8724d39f 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -844,7 +844,7 @@ emit_semaphore_wait(struct i915_request *to, intel_ring_advance(to, cs); } - to->sched.semaphore = true; + to->sched.semaphore |= I915_SCHED_HAS_SEMAPHORE; return 0; } @@ -867,6 +867,9 @@ i915_request_await_request(struct i915_request *to, struct i915_request *from) return ret; } + if (from->sched.semaphore && !i915_request_started(from)) + to->sched.semaphore |= I915_SCHED_CHAIN_SEMAPHORE; + if (to->engine == from->engine) { ret = i915_sw_fence_await_sw_fence_gfp(&to->submit, &from->submit, @@ -1117,6 +1120,9 @@ void i915_request_add(struct i915_request *request) if (engine->schedule) { struct i915_sched_attr attr = request->gem_context->sched; + if (!request->sched.semaphore) + attr.priority |= I915_PRIORITY_NOSEMAPHORE; + /* * Boost priorities to new clients (new request flows). * diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c index aa6c663dca09..4394763d10d8 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.c +++ b/drivers/gpu/drm/i915/i915_scheduler.c @@ -29,7 +29,7 @@ void i915_sched_node_init(struct i915_sched_node *node) INIT_LIST_HEAD(&node->waiters_list); INIT_LIST_HEAD(&node->link); node->attr.priority = I915_PRIORITY_INVALID; - node->semaphore = false; + node->semaphore = 0; } static struct i915_dependency * diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h index d764cf10536f..d84f09e8c248 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.h +++ b/drivers/gpu/drm/i915/i915_scheduler.h @@ -24,14 +24,15 @@ enum { I915_PRIORITY_INVALID = INT_MIN }; -#define I915_USER_PRIORITY_SHIFT 2 +#define I915_USER_PRIORITY_SHIFT 3 #define I915_USER_PRIORITY(x) ((x) << I915_USER_PRIORITY_SHIFT) #define I915_PRIORITY_COUNT BIT(I915_USER_PRIORITY_SHIFT) #define I915_PRIORITY_MASK (I915_PRIORITY_COUNT - 1) -#define I915_PRIORITY_WAIT ((u8)BIT(0)) -#define I915_PRIORITY_NEWCLIENT ((u8)BIT(1)) +#define I915_PRIORITY_WAIT ((u8)BIT(0)) +#define I915_PRIORITY_NEWCLIENT ((u8)BIT(1)) +#define I915_PRIORITY_NOSEMAPHORE ((u8)BIT(2)) struct i915_sched_attr { /** @@ -72,7 +73,9 @@ struct i915_sched_node { struct list_head waiters_list; /* those after us, they depend upon us */ struct list_head link; struct i915_sched_attr attr; - bool semaphore; + unsigned long semaphore; +#define I915_SCHED_HAS_SEMAPHORE BIT(0) +#define I915_SCHED_CHAIN_SEMAPHORE BIT(1) }; struct i915_dependency { diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 80d17b75b2e6..5bb3964bb202 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -164,7 +164,7 @@ #define WA_TAIL_DWORDS 2 #define WA_TAIL_BYTES (sizeof(u32) * WA_TAIL_DWORDS) -#define ACTIVE_PRIORITY (I915_PRIORITY_NEWCLIENT) +#define ACTIVE_PRIORITY (I915_PRIORITY_NEWCLIENT | I915_PRIORITY_NOSEMAPHORE) static int execlists_context_deferred_alloc(struct i915_gem_context *ctx, struct intel_engine_cs *engine, @@ -614,7 +614,8 @@ static bool can_merge_rq(const struct i915_request *prev, * rules should mean that if this semaphore is preempted, its * dependency chain is preserved and suitably promoted via PI. */ - if (prev->sched.semaphore && !i915_request_started(prev)) + if (prev->sched.semaphore & I915_SCHED_HAS_SEMAPHORE && + !i915_request_started(prev)) return false; if (!can_merge_ctx(prev->hw_context, next->hw_context)) -- 2.20.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
