drm/i915/gt: Drop stale commentary for timeline density

We no longer allocate a contiguous set of timeline ids for all engines
upon creation, so we no longer should assume that the timelines are
densely allocated within a context. Hopefully, the set of fences used
within a workload are still dense enough for us to take advantage of
the compressed radix tree used for the syncmap.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190625233349.32371-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_timeline.c

@@ -210,16 +210,6 @@ int intel_timeline_init(struct intel_timeline *timeline,
 {
 	void *vaddr;
 
-	/*
-	 * Ideally we want a set of engines on a single leaf as we expect
-	 * to mostly be tracking synchronisation between engines. It is not
-	 * a huge issue if this is not the case, but we may want to mitigate
-	 * any page crossing penalties if they become an issue.
-	 *
-	 * Called during early_init before we know how many engines there are.
-	 */
-	BUILD_BUG_ON(KSYNCMAP < I915_NUM_ENGINES);
-
 	timeline->gt = gt;
 	timeline->pin_count = 0;
 	timeline->has_initial_breadcrumb = !hwsp;