hipBLASLt environment variables#
This section describes the important hipBLASLt environment variables, which are grouped by functionality.
Logging and debugging#
The logging and debugging environment variables for hipBLASLt are collected in the following table. For more information, see Use logging and heuristics.
Environment variable |
Value |
|---|---|
HIPBLASLT_LOG_LEVELControls the verbosity level of hipBLASLt logging output.
|
0: Off (logging disabled, default)
1: Error (only errors are logged)
2: Trace (API calls with kernel launches log parameters)
3: Hints (performance improvement suggestions)
4: Info (general library execution information)
5: API trace (detailed API call parameters)
|
HIPBLASLT_LOG_MASKControls logging output using bit mask flags (can be combined).
|
0: Off
1: Error
2: Trace
4: Hints
8: Info
16: API trace
32: Bench
64: Profile
128: Extended profile
|
HIPBLASLT_LOG_FILESpecifies path to logging file. Can contain
%i for process ID replacement. |
Path to log file (for example,
logfile_%i.log)If not defined: log messages printed to stdout
|
HIPBLASLT_ENABLE_MARKEREnables marker trace for ROCProfiler profiling.
|
0 or unset: Disable marker trace
1: Enable marker trace
|
Offline tuning#
The offline tuning environment variables for hipBLASLt are collected in the following table. For more information, see Use hipBLASLt offline tuning.
Environment variable |
Value |
|---|---|
HIPBLASLT_TUNING_FILESpecifies file to store tuning results with best solution indices for GEMM problems.
|
Path to tuning file (for example,
tuning.txt)File stores optimal kernel indices for reuse
|
HIPBLASLT_TUNING_OVERRIDE_FILESpecifies file to load tuning results and override default kernel selection.
|
Path to tuning file (for example,
tuning.txt)Loads previously saved optimal kernel choices
|
HIPBLASLT_TUNING_USER_MAX_WORKSPACESets maximum workspace size constraint during tuning stage.
|
Integer value in bytes (default: 128 * 1024 * 1024)
Limits workspace size for solution selection
|
Stream-K configuration#
The Stream-K configuration environment variables for hipBLASLt are collected in the following table. For more information, see Use Stream-K with hipBLASLt.
Environment variable |
Value |
|---|---|
TENSILE_SOLUTION_SELECTION_METHODControls hipBLASLt kernel selection strategy for GEMM operations.
|
0: Default (standard tuned libraries, no Stream-K)
2: Stream-K (enables Stream-K library for consistent performance)
This variable has no effect on the AMD Instinct™ MI350 series. Stream-K is always used.
|
TENSILE_STREAMK_DYNAMIC_GRIDControls Stream-K dynamic grid size selection behavior.
|
0: Disable dynamic grid (use all available compute units)
3: Default (automatically pick optimal workgroup count)
|
TENSILE_STREAMK_FIXED_GRIDOverrides default grid size with specified number of workgroups for Stream-K kernels.
|
Integer value specifying number of workgroups
Example: 64 (limits GEMM kernels to 64 workgroups)
|
TENSILE_STREAMK_MAX_CUSSets maximum number of compute units for Stream-K kernels.
|
Integer value specifying maximum compute units
Example: 32 (limits GEMM kernels to 32 compute units)
Default: All available compute units
|