From f1ad5a1fd4127b3a5e21b8f5ef7f1921a5d3063e Mon Sep 17 00:00:00 2001 From: Oscar Mateo Date: Thu, 24 Jul 2014 17:04:41 +0100 Subject: [PATCH] drm/i915/bdw: Help out the ctx switch interrupt handler If we receive a storm of requests for the same context (see gem_storedw_loop_*) we might end up iterating over too many elements in interrupt time, looking for contexts to squash together. Instead, share the burden by giving more intelligence to the queue function. At most, the interrupt will iterate over three elements. Signed-off-by: Oscar Mateo Reviewed-by: Damien Lespiau [danvet: Checkpatch.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_lrc.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 0f1b6b2b0f0e..6f6c5a931faf 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -392,10 +392,10 @@ static int execlists_context_queue(struct intel_engine_cs *ring, struct intel_context *to, u32 tail) { - struct intel_ctx_submit_request *req = NULL; + struct intel_ctx_submit_request *req = NULL, *cursor; struct drm_i915_private *dev_priv = ring->dev->dev_private; unsigned long flags; - bool was_empty; + int num_elements = 0; req = kzalloc(sizeof(*req), GFP_KERNEL); if (req == NULL) @@ -410,9 +410,27 @@ static int execlists_context_queue(struct intel_engine_cs *ring, spin_lock_irqsave(&ring->execlist_lock, flags); - was_empty = list_empty(&ring->execlist_queue); + list_for_each_entry(cursor, &ring->execlist_queue, execlist_link) + if (++num_elements > 2) + break; + + if (num_elements > 2) { + struct intel_ctx_submit_request *tail_req; + + tail_req = list_last_entry(&ring->execlist_queue, + struct intel_ctx_submit_request, + execlist_link); + + if (to == tail_req->ctx) { + WARN(tail_req->elsp_submitted != 0, + "More than 2 already-submitted reqs queued\n"); + list_del(&tail_req->execlist_link); + queue_work(dev_priv->wq, &tail_req->work); + } + } + list_add_tail(&req->execlist_link, &ring->execlist_queue); - if (was_empty) + if (num_elements == 0) execlists_context_unqueue(ring); spin_unlock_irqrestore(&ring->execlist_lock, flags);