feature: enable defer backing by default

Related-To: NEO-13403

Signed-off-by: Bellekallu Rajkiran <bellekallu.rajkiran@intel.com>
Signed-off-by: Narendra Bagria <narendra.bagria@intel.com>

shared/source/debug_settings/debug_variables_base.inl

@@ -499,8 +499,8 @@ DECLARE_DEBUG_VARIABLE(bool, ForceSamplerLowFilteringPrecision, false, "Force Lo
 DECLARE_DEBUG_VARIABLE(bool, EnablePrivateBO, false, "Enable PRELIM_I915_GEM_CREATE_EXT_VM_PRIVATE extension creating VM_PRIVATE BOs")
 DECLARE_DEBUG_VARIABLE(bool, EnableAIL, true, "Enables AIL")
 DECLARE_DEBUG_VARIABLE(bool, EnableReservingInSvmRange, true, "Enables reserving virtual memory in the SVM range")
-DECLARE_DEBUG_VARIABLE(bool, EnableDeferBacking, false, "Enables defer backing on xe kmd")
 DECLARE_DEBUG_VARIABLE(bool, DisableProgrammableMetricsSupport, false, "Disable Programmable Metrics support")
+DECLARE_DEBUG_VARIABLE(int32_t, EnableDeferBacking, -1, "Enables defer backing on xe kmd, -1:default(enabled), 0:disable, 1:enable")
 DECLARE_DEBUG_VARIABLE(int64_t, VmBindWaitUserFenceTimeout, -1, "-1: default, >0: time in ns for wait function timeout")
 DECLARE_DEBUG_VARIABLE(int32_t, ForceRunAloneContext, -1, "Control creation of run-alone HW context, -1:default, 0:disable, 1:enable")
 DECLARE_DEBUG_VARIABLE(int32_t, AddClGlSharing, -1, "Add cl-gl extension")

shared/source/os_interface/linux/xe/ioctl_helper_xe.cpp

@@ -268,6 +268,11 @@ bool IoctlHelperXe::initialize() {
             assignValue(tileIdToMediaGtId, gt.tile_id, gt.gt_id);
         }
     }
+
+    if (debugManager.flags.EnableDeferBacking.get() != -1) {
+        enableDeferBacking = debugManager.flags.EnableDeferBacking.get();
+    }
+
     return true;
 }
 
@@ -650,7 +655,7 @@ int IoctlHelperXe::createGemExt(const MemRegionsVec &memClassInstances, size_t a
     create.placement = static_cast<uint32_t>(memoryInstances.to_ulong());
     create.cpu_caching = this->getCpuCachingMode(isCoherent, isSysMemOnly);
 
-    if (debugManager.flags.EnableDeferBacking.get()) {
+    if (enableDeferBacking) {
         create.flags |= DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING;
     }
 
@@ -696,7 +701,7 @@ uint32_t IoctlHelperXe::createGem(uint64_t size, uint32_t memoryBanks, std::opti
     create.placement = static_cast<uint32_t>(memoryInstances.to_ulong());
     create.cpu_caching = this->getCpuCachingMode(isCoherent, isSysMemOnly);
 
-    if (debugManager.flags.EnableDeferBacking.get()) {
+    if (enableDeferBacking) {
         create.flags |= DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING;
     }
 
@@ -1653,11 +1658,7 @@ bool IoctlHelperXe::isImmediateVmBindRequired() const {
 }
 
 bool IoctlHelperXe::makeResidentBeforeLockNeeded() const {
-    auto makeResidentBeforeLockNeeded = false;
+    return enableDeferBacking;
-    if (debugManager.flags.EnableDeferBacking.get()) {
-        makeResidentBeforeLockNeeded = true;
-    }
-    return makeResidentBeforeLockNeeded;
 }
 
 void IoctlHelperXe::insertEngineToContextParams(ContextParamEngines<> &contextParamEngines, uint32_t engineId, const EngineClassInstance *engineClassInstance, uint32_t tileId, bool hasVirtualEngines) {

shared/source/os_interface/linux/xe/ioctl_helper_xe.h

@@ -227,6 +227,8 @@ class IoctlHelperXe : public IoctlHelper {
     };
 
     std::unique_ptr<EuDebugInterface> euDebugInterface;
+
+    bool enableDeferBacking = true;
 };
 
 template <typename... XeLogArgs>

shared/test/common/test_files/igdrcl.config

@@ -648,7 +648,7 @@ EnableTimestampPoolAllocator = -1
 PipelinedEuThreadArbitration = -1
 ExperimentalUSMAllocationReuseCleaner = -1
 DummyPageBackingEnabled = 0
-EnableDeferBacking = 0
+EnableDeferBacking = -1
 ForceLowLatencyHint = -1
 EmitMemAdvisePriorToCopyForNonUsm = -1
 TreatNonUsmForTransfersAsSharedSystem = -1

shared/test/unit_test/os_interface/linux/xe/ioctl_helper_xe_tests.cpp

@@ -138,9 +138,6 @@ TEST_F(IoctlHelperXeGemCreateExtTests, givenIoctlHelperXeWhenCallingGemCreateExt
 }
 
 TEST_F(IoctlHelperXeGemCreateExtTests, givenIoctlHelperXeWhenCallingGemCreateExtWithOnlySystemRegionAndCoherencyThenWriteBackCPUCachingIsUsed) {
-    DebugManagerStateRestore restorer;
-    debugManager.flags.EnableDeferBacking.set(1);
-
     MemRegionsVec memRegions = {systemMemory};
     bool isCoherent = true;
 
@@ -149,10 +146,24 @@ TEST_F(IoctlHelperXeGemCreateExtTests, givenIoctlHelperXeWhenCallingGemCreateExt
     EXPECT_EQ(static_cast<uint32_t>(DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING), (drm->createParamsFlags & DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING));
 }
 
+TEST_F(IoctlHelperXeGemCreateExtTests, givenIoctlHelperXeAndDeferBackingIsDisabledWhenCallingGemCreateExtThenVerifyGemCreateFlagsAreNotSet) {
+    DebugManagerStateRestore restorer;
+    debugManager.flags.EnableDeferBacking.set(0);
+    auto executionEnvironment = std::make_unique<MockExecutionEnvironment>();
+    auto drm = DrmMockXe::create(*executionEnvironment->rootDeviceEnvironments[0]);
+    auto xeIoctlHelper = static_cast<MockIoctlHelperXe *>(drm->getIoctlHelper());
+    xeIoctlHelper->initialize();
+    MemRegionsVec memRegions = {systemMemory};
+    bool isCoherent = true;
+
+    EXPECT_NE(0, xeIoctlHelper->createGemExt(memRegions, allocSize, handle, patIndex, std::nullopt, pairHandle, isChunked, numOfChunks, std::nullopt, std::nullopt, isCoherent));
+    EXPECT_EQ(0u, drm->createParamsFlags);
+}
+
 TEST_F(IoctlHelperXeTest, givenIoctlHelperXeWhenCallGemCreateAndNoLocalMemoryThenProperValuesSet) {
     DebugManagerStateRestore restorer;
     debugManager.flags.EnableLocalMemory.set(0);
-    debugManager.flags.EnableDeferBacking.set(1);
+    debugManager.flags.EnableDeferBacking.set(0);
     auto executionEnvironment = std::make_unique<MockExecutionEnvironment>();
     auto drm = DrmMockXe::create(*executionEnvironment->rootDeviceEnvironments[0]);
     auto xeIoctlHelper = static_cast<MockIoctlHelperXe *>(drm->getIoctlHelper());
@@ -171,7 +182,7 @@ TEST_F(IoctlHelperXeTest, givenIoctlHelperXeWhenCallGemCreateAndNoLocalMemoryThe
     EXPECT_TRUE(xeIoctlHelper->bindInfo.empty());
 
     EXPECT_EQ(size, drm->createParamsSize);
-    EXPECT_EQ(static_cast<uint32_t>(DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING), (drm->createParamsFlags & DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING));
+    EXPECT_EQ(0u, drm->createParamsFlags);
     EXPECT_EQ(DRM_XE_GEM_CPU_CACHING_WC, drm->createParamsCpuCaching);
     EXPECT_EQ(1u, drm->createParamsPlacement);
 
@@ -183,7 +194,6 @@ TEST_F(IoctlHelperXeTest, givenIoctlHelperXeWhenCallGemCreateAndNoLocalMemoryThe
 TEST_F(IoctlHelperXeTest, givenIoctlHelperXeWhenCallGemCreateWhenMemoryBanksZeroThenProperValuesSet) {
     DebugManagerStateRestore restorer;
     debugManager.flags.EnableLocalMemory.set(0);
-    debugManager.flags.EnableDeferBacking.set(1);
     auto executionEnvironment = std::make_unique<MockExecutionEnvironment>();
     auto drm = DrmMockXe::create(*executionEnvironment->rootDeviceEnvironments[0]);
     auto xeIoctlHelper = static_cast<MockIoctlHelperXe *>(drm->getIoctlHelper());
@@ -214,7 +224,6 @@ TEST_F(IoctlHelperXeTest, givenIoctlHelperXeWhenCallGemCreateWhenMemoryBanksZero
 TEST_F(IoctlHelperXeTest, givenIoctlHelperXeWhenCallGemCreateAndLocalMemoryThenProperValuesSet) {
     DebugManagerStateRestore restorer;
     debugManager.flags.EnableLocalMemory.set(1);
-    debugManager.flags.EnableDeferBacking.set(1);
     auto executionEnvironment = std::make_unique<MockExecutionEnvironment>();
     auto drm = DrmMockXe::create(*executionEnvironment->rootDeviceEnvironments[0]);
     auto xeIoctlHelper = static_cast<MockIoctlHelperXe *>(drm->getIoctlHelper());
@@ -3007,15 +3016,24 @@ TEST_F(IoctlHelperXeTest, whenQueryDeviceIdAndRevisionAndSharedSystemUsmSupportD
     EXPECT_FALSE(drm->isSharedSystemAllocEnabled());
 }
 
-TEST_F(IoctlHelperXeTest, givenXeIoctlHelperAndDeferBackingFlagSetToTrueWhenMakeResidentBeforeLockNeededIsCalledThenVerifyTrueIsReturned) {
+TEST_F(IoctlHelperXeTest, givenXeIoctlHelperWhenMakeResidentBeforeLockNeededIsCalledThenVerifyTrueIsReturned) {
-    DebugManagerStateRestore restorer;
-    debugManager.flags.EnableDeferBacking.set(1);
     auto executionEnvironment = std::make_unique<MockExecutionEnvironment>();
-    DrmMock drm{*executionEnvironment->rootDeviceEnvironments[0]};
+    auto drm = DrmMockXe::create(*executionEnvironment->rootDeviceEnvironments[0]);
-    auto xeIoctlHelper = std::make_unique<IoctlHelperXe>(drm);
+    auto xeIoctlHelper = static_cast<MockIoctlHelperXe *>(drm->getIoctlHelper());
+    xeIoctlHelper->initialize();
     EXPECT_TRUE(xeIoctlHelper->makeResidentBeforeLockNeeded());
 }
 
+TEST_F(IoctlHelperXeTest, givenXeIoctlHelperAndDeferBackingFlagSetToFalseWhenMakeResidentBeforeLockNeededIsCalledThenVerifyTrueIsReturned) {
+    DebugManagerStateRestore restorer;
+    debugManager.flags.EnableDeferBacking.set(0);
+    auto executionEnvironment = std::make_unique<MockExecutionEnvironment>();
+    auto drm = DrmMockXe::create(*executionEnvironment->rootDeviceEnvironments[0]);
+    auto xeIoctlHelper = static_cast<MockIoctlHelperXe *>(drm->getIoctlHelper());
+    xeIoctlHelper->initialize();
+    EXPECT_FALSE(xeIoctlHelper->makeResidentBeforeLockNeeded());
+}
+
 TEST_F(IoctlHelperXeTest, givenXeIoctlHelperWhenCreateDrmContextAndLowLatencyHintNotAvailableThenNoFlagIsSet) {
     class MockLinuxOsContext : public OsContextLinux {
       public: