[PATCH] tests/intel/xe_exec_balancer: use xe_wait_ufence to replace sleep action

[Zongyao Bai]

    In the test_cm() function, for cases with the INVALIDATE flag,
    use sleep 0.25 seconds to allow all tasks to complete their jobs.
    However, this time is sometimes insufficient.

    In this patch, xe_wait_ufence (referred to as "fence" for short) actions are added
    for the second half of n_execs tasks in INVALIDATE-RACE scenarios.
    The changes are as follows:
        When flags hit nothing: => No change
             -- all n_exec tasks operate with a fence.
        When flags include INVALIDATE but do not include RACE: => No change
             -- the last n_exec task operates with a fence.
        When flags include both INVALIDATE and RACE => New in this patch
             -- n_execs/2 + 1 tasks operate with a fence.
             -- at least the last n_exec task operates with a fence
    Furthermore, modify the xe_wait_ufence timeout value from 1s to INT64_MAX.
    It helps avoid the fence timetout error.

    With the above changes, all n_exec tasks operate with a fence,
    allowing us to remove the sleep part.

Signed-off-by: Zongyao Bai <zongyao.bai at intel.com>
---
 tests/intel/xe_exec_balancer.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/tests/intel/xe_exec_balancer.c b/tests/intel/xe_exec_balancer.c
index 1747e207c..8b397038a 100644
--- a/tests/intel/xe_exec_balancer.c
+++ b/tests/intel/xe_exec_balancer.c
@@ -527,14 +527,17 @@ test_cm(int fd, int gt, int class, int n_exec_queues, int n_execs,
 		}
 	}
 
-	j = flags & INVALIDATE && n_execs ? n_execs - 1 : 0;
+	/* Wait for all execs to complete, and the xe_wait_ufence need to be run at least once. */
+	if (flags & INVALIDATE && n_execs) {
+		j = flags & RACE ? (n_execs/2 + 1) : n_execs-1;
+		if (j >= n_execs)
+			j = n_execs - 1;
+	} else {
+		j = 0;
+	}
 	for (i = j; i < n_execs; i++)
 		xe_wait_ufence(fd, &data[i].exec_sync, USER_FENCE_VALUE,
-			       exec_queues[i % n_exec_queues], NSEC_PER_SEC);
-
-	/* Wait for all execs to complete */
-	if (flags & INVALIDATE)
-		usleep(250000);
+			       exec_queues[i % n_exec_queues], INT64_MAX);
 
 	sync[0].addr = to_user_pointer(&data[0].vm_sync);
 	xe_vm_unbind_async(fd, vm, 0, 0, addr, bo_size, sync, 1);
-- 
2.43.0