From 43d4e71c6c8ad2876b6904bff68852066335ae30 Mon Sep 17 00:00:00 2001
From: Dmitry Vodopyanov <dmitry.vodopyanov@intel.com>
Date: Mon, 17 Jan 2022 20:24:54 +0300
Subject: [PATCH] [SYCL] Nullify Queue->LastCommandEvent in L0's piQueueFinish

Thus patch nullifies Queue->LastCommandEvent in Level Zero's
piQueueFinish as it was in _pi_event::cleanup to prevent extra batching
and performance drop.
---
 sycl/plugins/level_zero/pi_level_zero.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sycl/plugins/level_zero/pi_level_zero.cpp b/sycl/plugins/level_zero/pi_level_zero.cpp
index 6a1ed55462ddd..95657129b243d 100644
--- a/sycl/plugins/level_zero/pi_level_zero.cpp
+++ b/sycl/plugins/level_zero/pi_level_zero.cpp
@@ -3091,6 +3091,9 @@ pi_result piQueueFinish(pi_queue Queue) {
       ZE_CALL(zeHostSynchronize, (Queue->ZeCopyCommandQueues[i]));
   }
 
+  // Prevent unneeded already finished events to show up in the wait list.
+  Queue->LastCommandEvent = nullptr;
+
   return PI_SUCCESS;
 }