[Intel-gfx] [PATCH v10] drm/i915: Squash repeated awaits on the same fence

[Chris Wilson]

On Fri, Apr 28, 2017 at 10:55:09AM +0100, Tvrtko Ursulin wrote:
> 
> On 28/04/2017 08:41, Chris Wilson wrote:
> 
> [snip]
> 
> >+static int igt_sync(void *arg)
> >+{
> >+	const struct {
> >+		const char *name;
> >+		u32 seqno;
> >+		bool expected;
> >+		bool set;
> >+	} pass[] = {
> >+		{ "unset", 0, false, false },
> >+		{ "new", 0, false, true },
> >+		{ "0a", 0, true, true },
> >+		{ "1a", 1, false, true },
> >+		{ "1b", 1, true, true },
> >+		{ "0b", 0, true, false },
> >+		{ "2a", 2, false, true },
> >+		{ "4", 4, false, true },
> >+		{ "INT_MAX", INT_MAX, false, true },
> >+		{ "INT_MAX-1", INT_MAX-1, true, false },
> >+		{ "INT_MAX+1", (u32)INT_MAX+1, false, true },
> >+		{ "INT_MAX", INT_MAX, true, false },
> >+		{ "UINT_MAX", UINT_MAX, false, true },
> >+		{ "wrap", 0, false, true },
> >+		{ "unwrap", UINT_MAX, true, false },
> >+		{},
> >+	}, *p;
> >+	struct intel_timeline *tl;
> >+	int order, offset;
> >+	int ret;
> >+
> >+	tl = mock_timeline(0);
> >+	if (!tl)
> >+		return -ENOMEM;
> >+
> >+	for (p = pass; p->name; p++) {
> >+		for (order = 1; order < 64; order++) {
> >+			for (offset = -1; offset <= (order > 1); offset++) {
> >+				u64 ctx = BIT_ULL(order) + offset;
> >+
> >+				if (__intel_timeline_sync_is_later
> >+				    (tl, ctx, p->seqno) != p->expected) {
> >+					pr_err("1: %s(ctx=%llu, seqno=%u) expected passed %s but failed\n",
> >+					       p->name, ctx, p->seqno, yesno(p->expected));
> >+					ret = -EINVAL;
> >+					goto out;
> >+				}
> >+
> >+				if (p->set) {
> >+					ret = __intel_timeline_sync_set(tl, ctx, p->seqno);
> >+					if (ret)
> >+						goto out;
> >+				}
> >+			}
> >+		}
> >+	}
> 
> I think verification that the tree height matches the expectation,
> and also total number of nodes, is required.

That sounds a good excuse to start selftests/i915_syncmap

My primary goal here is to exercise the simpler intel_timeline_sync
interface, i.e. this portion should be agnostic to the implementation.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre