[UR] Add UR_L0_V2_DISABLE_ZE_LAUNCH_KERNEL_WITH_ARGS debugging variable

Add UR_L0_V2_DISABLE_ZE_LAUNCH_KERNEL_WITH_ARGS debugging environment variable
to disable calling ZeCommandListAppendLaunchKernelWithArguments().

Signed-off-by: Lukasz Dorau <[email protected]>

Author: ldorau

sycl/doc/EnvironmentVariables.md

@@ -272,6 +272,7 @@ older hardware or when SYCL_UR_USE_LEVEL_ZERO_V2=0 is set.</span>
 | Environment variable | Values | Description | Adapter Support |
 | -------------------- | ------ | ----------- | --------------- |
 | `UR_L0_V2_FORCE_DISABLE_COPY_OFFLOAD` | Integer | By default, copy operations submitted to any queue can be offloaded to dedicated copy engines. Setting this variable instructs the driver to keep all copy operations on the engine behind the original queue. The default value is 0. | V2 |
+| `UR_L0_V2_DISABLE_ZE_LAUNCH_KERNEL_WITH_ARGS` | Integer | By default, ZeCommandListAppendLaunchKernelWithArguments() will be called when available and possible. Setting this variable instructs the driver to not call ZeCommandListAppendLaunchKernelWithArguments() and use the old path using ZeCommandListAppendLaunchKernel(). The default value is 0. | V2 |
 | `SYCL_PI_LEVEL_ZERO_SINGLE_THREAD_MODE` | Integer | A single-threaded app has an opportunity to enable this mode to avoid overhead from mutex locking in the Level Zero adapter. A value greater than 0 enables single thread mode. A value of 0 disables single thread mode. The default is 0. | Legacy |
 | `SYCL_PI_LEVEL_ZERO_USM_ALLOCATOR` | [EnableBuffers][;[MaxPoolSize][;[host\|device\|shared:][MaxPoolableSize][,[Capacity][,SlabMinSize]]]...] | EnableBuffers enables pooling for SYCL buffers, default 1, set to 0 to disable. MaxPoolSize is the maximum size of the pool, by default there is no size limit. MemType is host, device, shared or read_only_shared. Other parameters are values specified as positive integers with optional K, M or G suffix. MaxPoolableSize is the maximum allocation size that may be pooled, default 0 for shared, 2MB for host, 4MB for device and read_only_shared. Capacity is the number of allocations in each size range freed by the program but retained in the pool for reallocation, default 4. Size ranges follow this pattern: 64, 96, 128, 192, and so on, i.e., powers of 2, with one range in between. SlabMinSize is the minimum allocation size, 64KB for host and device, 2MB for shared and read_only_shared. Example: SYCL_PI_LEVEL_ZERO_USM_ALLOCATOR=1;32M;host:1M,4,64K;device:1M,4,64K;shared:0,0,2M| Legacy and V2 |
 | `SYCL_PI_LEVEL_ZERO_BATCH_SIZE` | Integer | Sets a preferred number of compute commands to batch into a command list before executing the command list. A value of 0 causes the batch size to be adjusted dynamically. A value greater than 0 specifies fixed size batching, with the batch size set to the specified value. The default is 0. | Legacy |

unified-runtime/source/adapters/level_zero/v2/command_list_manager.cpp

@@ -1250,14 +1250,20 @@ ur_result_t ur_command_list_manager::appendKernelLaunchWithArgsExp(
     cooperativeKernelLaunchRequested = true;
   }
 
+  int DisableZeLaunchKernelWithArgs = 0;
+  if (auto DisableZeLaunchKernelWithArgsVal =
+          std::getenv("UR_L0_V2_DISABLE_ZE_LAUNCH_KERNEL_WITH_ARGS")) {
+    DisableZeLaunchKernelWithArgs = std::atoi(DisableZeLaunchKernelWithArgsVal);
+  }
+
   ur_platform_handle_t hPlatform = hContext->getPlatform();
   bool KernelWithArgsSupported =
       hPlatform->ZeCommandListAppendLaunchKernelWithArgumentsExt.Supported;
   bool CooperativeCompatible =
       hPlatform->ZeCommandListAppendLaunchKernelWithArgumentsExt
           .DriverSupportsCooperativeKernelLaunchWithArgs;
   bool RunNewPath =
-      KernelWithArgsSupported &&
+      !DisableZeLaunchKernelWithArgs && KernelWithArgsSupported &&
       (!cooperativeKernelLaunchRequested ||
        (cooperativeKernelLaunchRequested && CooperativeCompatible));
   if (RunNewPath) {