Logging in rocBLAS

Logging in rocBLAS#

Note that performance will degrade when logging is enabled.

User can set four environment variables to control logging:





ROCBLAS_LAYER is a bitwise OR of zero or more bit masks as follows:

  • If ROCBLAS_LAYER is not set, then there is no logging.

  • If (ROCBLAS_LAYER & 1) != 0, then there is trace logging.

  • If (ROCBLAS_LAYER & 2) != 0, then there is bench logging.

  • If (ROCBLAS_LAYER & 4) != 0, then there is profile logging.

Trace logging outputs a line each time a rocBLAS function is called. The line contains the function name and the values of arguments.

Bench logging outputs a line each time a rocBLAS function is called. The line can be used with the executable rocblas-bench to call the function with the same arguments.

Profile logging, at the end of program execution, outputs a YAML description of each rocBLAS function called, the values of its performance-critical arguments, and the number of times it was called with those arguments (the call_count). Some arguments, such as alpha and beta in GEMM, are recorded with a value representing the category that the argument falls in, such as -1, 0, 1, or 2. The number of categories, and the values representing them, may change over time, depending on how many categories are needed to adequately represent all the values that can affect the performance of the function.

The default stream for logging output is standard error. Three environment variables can set the full path name for a log file:

  • ROCBLAS_LOG_TRACE_PATH sets the full path name for trace logging.

  • ROCBLAS_LOG_BENCH_PATH sets the full path name for bench logging.

  • ROCBLAS_LOG_PROFILE_PATH sets the full path name for profile logging.

For example, in Bash shell, to output bench logging to the file bench_logging.txt in your present working directory:

  • export ROCBLAS_LOG_BENCH_PATH=$PWD/bench_logging.txt

Note that a full path is required, not a relative path. In the above command $PWD expands to the full path of your present working directory. If paths are not set, then the logging output is streamed to standard error.

When profile logging is enabled, memory usage increases. If the program exits abnormally, then it is possible that profile logging will not be outputted before the program exits.