CUDA Profiler Tools Interface (CUPTI) for CUDA Toolkit 12.3 is now available

CUDA Profiler Tools Interface (CUPTI) for CUDA Toolkit 12.3 is now available for download in the NVIDIA Registered Developer Program.

The NVIDIA CUDA Profiler Tools Interface (CUPTI) for CUDA Toolkit 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,
  • the Profiler API,
  • the PC Sampling API,
  • the SASS Metric API, and
  • the Checkpoint 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.

Updates in CUDA Toolkit 12.3 Update 1

    Resolved Issues
    • To provide normalized timestamps for all activities, CUPTI uses linear interpolation for conversion from GPU timestamps to CPU timestamps. This was broken with CUDA 12.3 causing spurious gaps or overlap on Tegra platforms. Fixed the issue.

Updates in CUDA Toolkit 12.3

    New Features
    • New attributes:
        CUPTI_ACTIVITY_OVERHEAD_RUNTIME_TRIGGERED_MODULE_LOADING and CUPTI_ACTIVITY_OVERHEAD_LAZY_FUNCTION_LOADING are added in the activity overhead enum CUpti_ActivityOverheadKind to provide the overhead information for CUDA runtime triggered module loading and lazy function loading respectively.
    • New API cuptiGetGraphExecId provides the unique ID of the executable graph.
    • Added support for collecting graph level trace for device launched graphs. A new API cuptiActivityEnableDeviceGraph is added to enable the collection of records for device launched graphs.
    • CUDA Graphs can be executed on multiple devices i.e. the root node could be launched on one device and the leaf node could be launched on the another device. New fields endDeviceId and endContextId are added to identify the ids of device and context respectively which are used to execute the last node of the graph. To accomodate this change, activity record CUpti_ActivityGraphTrace is deprecated and it is replaced by a new activity record CUpti_ActivityGraphTrace2.
    • Added WSL profiling support on Windows 10 WSL with OS build version 19044 and greater. WSL profiling is not supported on Windows 10 WSL for systems that exceed 1 TB of system memory.
    • Several performance improvements are done in the tracing path. One of the key improvements is to allow clients to request CUPTI to maintain the activity buffers at the thread level instead of global buffers. This can be achieved by setting the option CUPTI_ACTIVITY_ATTR_PER_THREAD_ACTIVITY_BUFFER of the enum CUpti_ActivityAttribute. This can help in reducing the collection overhead for applications which launch CUDA activities from multiple host threads.
    • Frame pointers are enabled for Linux x86_64 libraries.
    • The deprecated Activity APIs and structures have been moved to a new header cupti_activity_deprecated.h, which is included in the header cupti_activity.h. Header cupti_activity.h contains only the latest version of APIs and structures.
    • CUPTI no longer uses profiling semaphore pool to store the profiling data. Coresponding attributes CUPTI_ACTIVITY_ATTR_PROFILING_SEMAPHORE_POOL_SIZE, CUPTI_ACTIVITY_ATTR_PROFILING_SEMAPHORE_POOL_LIMIT and CUPTI_ACTIVITY_ATTR_PROFILING_SEMAPHORE_PRE_ALLOCATE_VALUE have been deprecated.
    Resolved Issues
    • Fixed SASS metric profiling for cuda graph.
    • Fixed race condition in the API cuptiSetThreadIdType for late subscription

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