From: Chris Wilson Date: Thu, 28 Apr 2016 08:56:49 +0000 (+0100) Subject: drm/i915: Preallocate enough space for the average request X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6310346e75cabb79f1c6acb3f801eecda09f0980;p=linux-beck.git drm/i915: Preallocate enough space for the average request Rather than being interrupted when we run out of space halfway through the request, and having to restart from the beginning (and returning to userspace), flush a little more free space when we prepare the request. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: http://patchwork.freedesktop.org/patch/msgid/1461833819-3991-15-git-send-email-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 413985832351..4dedeaa3c788 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -700,6 +700,12 @@ int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request { int ret; + /* Flush enough space to reduce the likelihood of waiting after + * we start building the request - in which case we will just + * have to repeat work. + */ + request->reserved_space += MIN_SPACE_FOR_ADD_REQUEST; + request->ringbuf = request->ctx->engine[request->engine->id].ringbuf; if (i915.enable_guc_submission) { @@ -725,6 +731,7 @@ int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request if (ret) goto err_unpin; + request->reserved_space -= MIN_SPACE_FOR_ADD_REQUEST; return 0; err_unpin: diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index c2a699230809..b5e79ac29ebc 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -2339,8 +2339,22 @@ int intel_engine_idle(struct intel_engine_cs *engine) int intel_ring_alloc_request_extras(struct drm_i915_gem_request *request) { + int ret; + + /* Flush enough space to reduce the likelihood of waiting after + * we start building the request - in which case we will just + * have to repeat work. + */ + request->reserved_space += MIN_SPACE_FOR_ADD_REQUEST; + request->ringbuf = request->engine->buffer; - return intel_ring_begin(request, 0); + + ret = intel_ring_begin(request, 0); + if (ret) + return ret; + + request->reserved_space -= MIN_SPACE_FOR_ADD_REQUEST; + return 0; } static int wait_for_space(struct drm_i915_gem_request *req, int bytes)