From 6310346e75cabb79f1c6acb3f801eecda09f0980 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 28 Apr 2016 09:56:49 +0100 Subject: [PATCH] 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 --- drivers/gpu/drm/i915/intel_lrc.c | 7 +++++++ drivers/gpu/drm/i915/intel_ringbuffer.c | 16 +++++++++++++++- 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 4139858323513..4dedeaa3c788e 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 c2a699230809c..b5e79ac29ebc9 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) -- 2.30.2