Best Practice for testing Managed Buffers?-CodePudding

The

Note:

In a unified memory model, Metal may ignore synchronization calls completely because it only creates a single memory allocation for the resource.

You can also check some implementations by other developers:

PixarAnimationStudios/USD:

HgiMetalCapabilities::HgiMetalCapabilities(id<MTLDevice> device) { if (@available(macOS 10.14.5, ios 12.0, *)) { _SetFlag(HgiDeviceCapabilitiesBitsConcurrentDispatch, true); } defaultStorageMode = MTLResourceStorageModeShared; bool unifiedMemory = false; if (@available(macOS 100.100, ios 12.0, *)) { unifiedMemory = true; } else if (@available(macOS 10.15, ios 13.0, *)) { #if defined(ARCH_OS_IOS) || (defined(__MAC_10_15) && __MAC_OS_X_VERSION_MAX_ALLOWED >= __MAC_10_15) unifiedMemory = [device hasUnifiedMemory]; #else unifiedMemory = [device isLowPower]; #endif } _SetFlag(HgiDeviceCapabilitiesBitsUnifiedMemory, unifiedMemory); #if defined(ARCH_OS_MACOS) if (!unifiedMemory) { defaultStorageMode = MTLResourceStorageModeManaged; } #endif }

KhronosGroup/MoltenVK

// Metal Managed: // - applies to both buffers and textures // - default mode for textures on macOS // - two copies of each buffer or texture when discrete memory available // - convenience of shared mode, performance of private mode // - on unified systems behaves like shared memory and has only one copy of content // - when writing, use: // - buffer didModifyRange: // - texture replaceRegion: // - when reading, use: // - encoder synchronizeResource: followed by // - cmdbuff waitUntilCompleted (or completion handler) // - buffer/texture getBytes: