[igt-dev] [PATCH i-g-t] tests/gem_exec_nop: "headless" requires submicrosecond precision

[Janusz Krzysztofik]

Commit 16f067ae42a6 ("i915/gem_exec_nop: Remove submission batching")
claimed to address the requirement of "headless" subtest for more
precise time measurement by keeping submission batching for it in
place.  Unfortunately, that was not implemented and the requirement
is now not addressed.

Check how many requests can be submitted per second and skip the
subtest if less than 1000.

Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
---
 tests/i915/gem_exec_nop.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tests/i915/gem_exec_nop.c b/tests/i915/gem_exec_nop.c
index 1c17d023d..2586db2d2 100644
--- a/tests/i915/gem_exec_nop.c
+++ b/tests/i915/gem_exec_nop.c
@@ -377,6 +377,8 @@ stable_nop_on_ring(int fd, uint32_t handle,
 		double time;
 
 		time = nop_on_ring(fd, handle, e, timeout, &count);
+		igt_skip_on_f(count < 1000 * timeout,
+			      "submicrosecond precision of time measurement\n");
 		igt_stats_push_float(&s, time / count);
 	}
 
-- 
2.21.1