NVIDIA CUDA Profiling Tools Interface (CUPTI) - CUDA Toolkit
The NVIDIA® CUDA Profiling Tools Interface (CUPTI) is a dynamic library that enables the creation of profiling and tracing tools that target CUDA applications. CUPTI provides a set of APIs targeted at ISVs creating profilers and other performance optimization tools:
- the Activity API,
- the Callback API,
- the Event API,
- the Metric API, and
- the Profiler API
Using these CUPTI APIs, independent software developers can create profiling tools that provide low and deterministic profiling overhead on the target system, while giving insight into the CPU and GPU behavior of CUDA applications. Normally packaged with the CUDA Toolkit, this stand-alone version of CUPTI provides improvements and bug fixes between toolkit releases.
- Trace CUDA API usage by registering callbacks for API calls of interest
- Full support for entry and exit points in the CUDA C Runtime (CUDART) and CUDA Driver
- Sample hardware and software event counters, including:
- Instruction count and throughput
- Memory load/store events and throughput
- Cache hits/misses
- Branches and divergent branches
- Many more
- Enables automated bottleneck identification based on metrics such as instruction throughput, memory throughput, and more
- Normalized timestamps for CPU and GPU events
As part of the CUDA Toolkit 11.0 release,
- CUPTI adds tracing and profiling support for devices with compute capability 8.0 i.e. NVIDIA A100 GPUs and systems that are based on A100.
- CUPTI adds support for the Arm server platform (arm64 SBSA).
- Enhancements for CUDA Graph:
- Support to correlate the CUDA Graph node with the GPU activities: kernel, memcpy, memset.
- Added a new field graphNodeId for Node Id in the activity records for kernel, memcpy, memset and P2P transfers. Activity records CUpti_ActivityKernel4, CUpti_ActivityMemcpy2, CUpti_ActivityMemset, and CUpti_ActivityMemcpyPtoP are deprecated and replaced by new activity records CUpti_ActivityKernel5, CUpti_ActivityMemcpy3, CUpti_ActivityMemset2, and CUpti_ActivityMemcpyPtoP2.
- graphNodeId is the unique ID for the graph node.
- graphNodeId can be queried using the new CUPTI API cuptiGetGraphNodeId().
- Callback CUPTI_CBID_RESOURCE_GRAPHNODE_CREATED is issued between a pair of the API enter and exit callbacks.
- Introduced new callback CUPTI_CBID_RESOURCE_GRAPHNODE_CLONED to indicate the cloning of the CUDA Graph node.
- Retain CUDA driver performance optimization in case memset node is sandwiched between kernel nodes. CUPTI no longer disables the conversion of memset nodes into kernel nodes for CUDA graphs.
- Added support for cooperative kernels in CUDA graphs.
- Fixed issues in the API cuptiFinalize() including the issue which may cause the application to crash. This API provides ability for safe and full detach of CUPTI during the execution of the application. More details in the section Dynamic Detach.
- Added support to trace Optix applications. Refer the Optix Profiling section.
- PC sampling overhead is reduced by avoiding the reconfiguration of the GPU when PC sampling period doesn't change between successive kernels. This is applicable for devices with compute capability 7.0 and higher.
- CUPTI overhead is associated with the thread rather than process. Object kind of the overhead record CUpti_ActivityOverhead is switched to CUPTI_ACTIVITY_OBJECT_THREAD.
- Added error code CUPTI_ERROR_MULTIPLE_SUBSCRIBERS_NOT_SUPPORTED to indicate the presense of another CUPTI subscriber. API cuptiSubscribe() returns the new error code than CUPTI_ERROR_MAX_LIMIT_REACHED.
- Added a new enum CUpti_FuncShmemLimitConfig to indicate whether user has opted in for maximun dynamic shared memory size on devices with compute capability 7.x by using function attributes CU_FUNC_ATTRIBUTE_MAX_DYNAMIC_SHARED_SIZE_BYTES or cudaFuncAttributeMaxDynamicSharedMemorySize with CUDA driver and runtime respectively. Field shmemLimitConfig in the kernel activity record CUpti_ActivityKernel5 shows the user choice. This helps in correct occupancy calulation. Value FUNC_SHMEM_LIMIT_OPTIN in the enum cudaOccFuncShmemConfig is the corresponding option in the CUDA occupancy calculator.
- Linux x86_64
- Windows x86_64
- Linux PowerPC
- Linux aarch64 SBSA
- DRIVE OS QNX aarch64
- DRIVE OS Linux aarch64
- Android aarch64
 available in the Embedded or Drive toolkits only
 does not support Profiling API data collection
Supported NVIDIA GPU architectures
- Activity and Callback APIs
- All architectures supported by CUDA Toolkit
- Event and Metric APIs
- Profiling APIs
- Volta: GV100
- CUPTI can be found in the CUDA Toolkit 11.0 production release
Please use the following drivers
- 451.12 (Windows)
- 450.36.01 (Linux)
To provide feedback, request additional features, or report issues, please use the Developer Forums.
When installing CUDA Toolkit 11.0 and specifying options, be sure to select CUDA > Development > Tools > CUPTI.