Environment variables¶
Behavior of dpctl is affected by environment variables that
affect DPC++ compiler runtime.
Variable ONEAPI_DEVICE_SELECTOR¶
The variable ONEAPI_DEVICE_SELECTOR can be used to limit the choice of devices
available to dpctl. Please refer to
Managing Devices for detailed
description and uses.
Variable SYCL_CACHE_PERSISTENT¶
The binaries implementing dpctl.tensor created using DPC++ compiler contain sections
with standardized intermediate forms (e.g. SPIR-V) that must be
further built using SYCL device drivers for execution on the specific target hardware.
This step is known as just-in-time compiling (JIT-ing).
By default, the result of JIT-ing persists for the duration of SYCL application, i.e. for the
duration of the Python session where dpctl.tensor is used. Setting environment variable
SYCL_CACHE_PERSISTENT to value of 1 instructs DPC++ runtime to save the result of JIT-ing to
disk and reuse it in subsequent Python sessions (assuming the variable remains to be set when sessions
are started).
Setting of the environment variable SYCL_CACHE_PERSISTENT improves times of function invocations,
but requires sufficient disk space. The size of the disk footprint can be controlled using
SYCL_CACHE_MAX_SIZE.
Variable SYCL_PI_TRACE¶
Setting this debugging variable enables specific levels of tracing for SYCL Programming Interfaces (PI). The value of the variable is a bit-mask, with the following supported values
Value |
Description |
|---|---|
|
Enables tracing of PI plugins/devices discovery |
|
Enables tracing of PI calls |
|
Enables all levels of tracing |