Edit

ID3D12Device6::SetBackgroundProcessingMode method (d3d12.h)

  • Article

Sets the mode for driver background processing optimizations.

Syntax

HRESULT SetBackgroundProcessingMode(
  [in]  D3D12_BACKGROUND_PROCESSING_MODE Mode,
  [in]  D3D12_MEASUREMENTS_ACTION        MeasurementsAction,
  [in]  HANDLE                           hEventToSignalUponCompletion,
  [out] BOOL                             *pbFurtherMeasurementsDesired
);

Parameters

[in] Mode

Type: D3D12_BACKGROUND_PROCESSING_MODE

The level of dynamic optimization to apply to GPU work that's subsequently submitted.

[in] MeasurementsAction

Type: D3D12_MEASUREMENTS_ACTION

The action to take with the results of earlier workload instrumentation.

[in] hEventToSignalUponCompletion

Type: HANDLE

An optional handle to signal when the function is complete. For example, if MeasurementsAction is set to D3D12_MEASUREMENTS_ACTION_COMMIT_RESULTS, then hEventToSignalUponCompletion is signaled when all resulting compilations have finished.

[out] pbFurtherMeasurementsDesired

Type: BOOL*

An optional pointer to a Boolean value. The function sets the value to true to indicate that you should continue profiling, otherwise, false.

Remarks

A graphics driver can use idle-priority background CPU threads to dynamically recompile shader programs. That can improve GPU performance by specializing shader code to better match details of the hardware that it's running on, and/or the context in which it's being used.

As a developer, you don't have to do anything to benefit from this feature (over time, as drivers adopt background processing optimizations, existing shaders will automatically be tuned more efficiently). But, when you're profiling your code, you'll probably want to call SetBackgroundProcessingMode to make sure that any driver background processing optimizations have taken place before you take timing measurements. Here's an example.

SetBackgroundProcessingMode(
    D3D12_BACKGROUND_PROCESSING_MODE_ALLOW_INTRUSIVE_MEASUREMENTS,
    D3D_MEASUREMENTS_ACTION_KEEP_ALL,
    nullptr, nullptr);
 
// Here, prime the system by rendering some typical content.
// For example, a level flythrough.
 
SetBackgroundProcessingMode(
    D3D12_BACKGROUND_PROCESSING_MODE_ALLOWED,
    D3D12_MEASUREMENTS_ACTION_COMMIT_RESULTS,
    nullptr, nullptr);
 
// Here, continue rendering. This time with dynamic optimizations applied.
// And then take your measurements.

PIX automatically uses SetBackgroundProcessingMode—first to prime the system,and then to prevent any further changes from taking place in the middle of its analysis. PIX waits on an event (to make sure all background shader recompiles have finished) before it starts taking measurements.

Requirements

Requirement Value
Minimum supported client Windows 10 Build 20348
Minimum supported server Windows 10 Build 20348
Target Platform Windows
Header d3d12.h
Library d3d12.lib
DLL d3d12.dll