igt/gem_exec_nop: Refine the target calculation
The ideal execution time cannot be faster than the fastest ring! If all
other rings were infinitely fast, the seed would be max/nengine. Given
each is finite, this puts a floor on the ideal execution time.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/tests/gem_exec_nop.c b/tests/gem_exec_nop.c
index 451cb47..f4f7a0f 100644
--- a/tests/gem_exec_nop.c
+++ b/tests/gem_exec_nop.c
@@ -252,7 +252,7 @@
time = elapsed(&start, &now) / count;
igt_info("All (%d engines): %'lu cycles, average %.3fus per cycle [expected ideal %.3fus]\n",
- nengine, count, 1e6*time, 1e6*max/nengine);
+ nengine, count, 1e6*time, 1e6*((max-min)/nengine+min));
/* The rate limiting step should be how fast the slowest engine can
* execute its queue of requests, as when we wait upon a full ring all