Commit 0c8dac88 authored May 29, 2015 by John Harrison Committed by Daniel Vetter Jun 23, 2015

drm/i915: Early alloc request in execbuff



Start of explicit request management in the execbuffer code path. This patch
adds a call to allocate a request structure before all the actual hardware work
is done. Thus guaranteeing that all that work is tagged by a known request. At
present, nothing further is done with the request, the rest comes later in the
series.

The only noticable change is that failure to get a request (e.g. due to lack of
memory) will be caught earlier in the sequence. It now occurs right at the start
before any un-undoable work has been done.

v2: Simplified the error handling path.

For: VIZ-5115
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Tomas Elf <tomas.elf@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

parent bf7dc5b7

drivers/gpu/drm/i915/i915_gem_execbuffer.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -1611,10 +1611,16 @@ i915_gem_do_execbuffer(struct drm_device dev, void data,
		} else
		exec_start += i915_gem_obj_offset(batch_obj, vm);

		/* Allocate a request for this batch buffer nice and early. */
		ret = i915_gem_request_alloc(ring, ctx);
		if (ret)
		goto err_batch_unpin;

		ret = dev_priv->gt.execbuf_submit(dev, file, ring, ctx, args,
		&eb->vmas, batch_obj, exec_start,
		dispatch_flags);

		err_batch_unpin:
		/*
		* FIXME: We crucially rely upon the active tracking for the (ppgtt)
		* batch vma for correctness. For less ugly and less fragility this
		@@ -1623,6 +1629,7 @@ i915_gem_do_execbuffer(struct drm_device dev, void data,
		*/
		if (dispatch_flags & I915_DISPATCH_SECURE)
		i915_gem_object_ggtt_unpin(batch_obj);

		err:
		/* the request owns the ref now */
		i915_gem_context_unreference(ctx);