Adding debug flag to disable DC flush in epilogue

Change-Id: I1784be279ee9f837a0994997bec49c1925a68390

Author: jchodor

runtime/command_stream/command_stream_receiver_hw.inl

@@ -563,7 +563,11 @@ inline void CommandStreamReceiverHw<GfxFamily>::flushBatchedSubmissions() {
 
             //make sure we flush DC if needed
             if (epiloguePipeControlLocation) {
-                ((PIPE_CONTROL *)epiloguePipeControlLocation)->setDcFlushEnable(false == HwHelper::cacheFlushAfterWalkerSupported(this->hwInfo));
+                bool flushDcInEpilogue = true;
+                if (DebugManager.flags.DisableDcFlushInEpilogue.get()) {
+                    flushDcInEpilogue = false;
+                }
+                ((PIPE_CONTROL *)epiloguePipeControlLocation)->setDcFlushEnable(flushDcInEpilogue);
             }
             auto flushStamp = this->flush(primaryCmdBuffer->batchBuffer, surfacesForSubmit);
 

runtime/os_interface/debug_variables_base.inl

@@ -80,6 +80,7 @@ DECLARE_DEBUG_VARIABLE(bool, UseNoRingFlushesKmdMode, true, "Windows only, passe
 DECLARE_DEBUG_VARIABLE(bool, DisableZeroCopyForUseHostPtr, false, "When active all buffer allocations created with CL_MEM_USE_HOST_PTR flag will not share memory with CPU.")
 DECLARE_DEBUG_VARIABLE(bool, DisableZeroCopyForBuffers, false, "When active all buffer allocations will not share memory with CPU.")
 DECLARE_DEBUG_VARIABLE(bool, EnableHostPtrTracking, true, "Enable host ptr tracking")
+DECLARE_DEBUG_VARIABLE(bool, DisableDcFlushInEpilogue, false, "Disable DC flush in epilogue")
 
 /*FEATURE FLAGS*/
 DECLARE_DEBUG_VARIABLE(bool, EnableNV12, true, "Enables NV12 extension")

unit_tests/command_stream/command_stream_receiver_flush_task_3_tests.cpp

@@ -918,6 +918,79 @@ HWTEST_F(CommandStreamReceiverFlushTaskTests, givenCsrInBatchingModeWhenDcFlushI
     EXPECT_NE(nullptr, cmdBuffer->epiloguePipeControlLocation);
 }
 
+HWTEST_F(CommandStreamReceiverFlushTaskTests, givenEpiloguePipeControlThenDcFlushIsEnabled) {
+    using PIPE_CONTROL = typename FamilyType::PIPE_CONTROL;
+
+    CommandQueueHw<FamilyType> commandQueue(nullptr, pDevice, 0);
+    auto &commandStream = commandQueue.getCS(4096u);
+
+    auto mockCsr = new MockCsrHw2<FamilyType>(*platformDevices[0], *pDevice->executionEnvironment);
+    pDevice->resetCommandStreamReceiver(mockCsr);
+
+    mockCsr->overrideDispatchPolicy(DispatchMode::BatchedDispatch);
+
+    auto mockedSubmissionsAggregator = new mockSubmissionsAggregator();
+    mockCsr->overrideSubmissionAggregator(mockedSubmissionsAggregator);
+
+    DispatchFlags dispatchFlags;
+    dispatchFlags.guardCommandBufferWithPipeControl = true;
+    dispatchFlags.outOfOrderExecutionAllowed = false;
+    dispatchFlags.preemptionMode = PreemptionHelper::getDefaultPreemptionMode(pDevice->getHardwareInfo());
+    mockCsr->flushTask(commandStream,
+                       0,
+                       dsh,
+                       ioh,
+                       ssh,
+                       taskLevel,
+                       dispatchFlags,
+                       *pDevice);
+
+    auto cmdBuffer = mockedSubmissionsAggregator->peekCommandBuffers().peekHead();
+    ASSERT_NE(nullptr, cmdBuffer->epiloguePipeControlLocation);
+    auto pipeControl = genCmdCast<PIPE_CONTROL *>(cmdBuffer->epiloguePipeControlLocation);
+    ASSERT_NE(nullptr, pipeControl);
+    mockCsr->flushBatchedSubmissions();
+    EXPECT_TRUE(pipeControl->getDcFlushEnable());
+}
+
+HWTEST_F(CommandStreamReceiverFlushTaskTests, givenEpiloguePipeControlWhendDcFlushDisabledByDebugFlagThenDcFlushIsDisabled) {
+    using PIPE_CONTROL = typename FamilyType::PIPE_CONTROL;
+
+    DebugManagerStateRestore debugRestorer;
+    DebugManager.flags.DisableDcFlushInEpilogue.set(true);
+
+    CommandQueueHw<FamilyType> commandQueue(nullptr, pDevice, 0);
+    auto &commandStream = commandQueue.getCS(4096u);
+
+    auto mockCsr = new MockCsrHw2<FamilyType>(*platformDevices[0], *pDevice->executionEnvironment);
+    pDevice->resetCommandStreamReceiver(mockCsr);
+
+    mockCsr->overrideDispatchPolicy(DispatchMode::BatchedDispatch);
+
+    auto mockedSubmissionsAggregator = new mockSubmissionsAggregator();
+    mockCsr->overrideSubmissionAggregator(mockedSubmissionsAggregator);
+
+    DispatchFlags dispatchFlags;
+    dispatchFlags.guardCommandBufferWithPipeControl = true;
+    dispatchFlags.outOfOrderExecutionAllowed = false;
+    dispatchFlags.preemptionMode = PreemptionHelper::getDefaultPreemptionMode(pDevice->getHardwareInfo());
+    mockCsr->flushTask(commandStream,
+                       0,
+                       dsh,
+                       ioh,
+                       ssh,
+                       taskLevel,
+                       dispatchFlags,
+                       *pDevice);
+
+    auto cmdBuffer = mockedSubmissionsAggregator->peekCommandBuffers().peekHead();
+    ASSERT_NE(nullptr, cmdBuffer->epiloguePipeControlLocation);
+    auto pipeControl = genCmdCast<PIPE_CONTROL *>(cmdBuffer->epiloguePipeControlLocation);
+    ASSERT_NE(nullptr, pipeControl);
+    mockCsr->flushBatchedSubmissions();
+    EXPECT_FALSE(pipeControl->getDcFlushEnable());
+}
+
 HWTEST_F(CommandStreamReceiverFlushTaskTests,
          givenCsrInBatchingModeAndOoqFlagSetToFalseWhenTwoTasksArePassedWithTheSameLevelThenThereIsPipeControlBetweenThemAfterFlush) {
     CommandQueueHw<FamilyType> commandQueue(nullptr, pDevice, 0);

unit_tests/test_files/igdrcl.config

@@ -106,3 +106,4 @@ AUBDumpAllocsOnEnqueueReadOnly = 0
 AUBDumpForceAllToLocalMemory = 0
 EnableCacheFlushAfterWalker = 0
 EnableHostPtrTracking = 1
+DisableDcFlushInEpilogue = 0