NAME
libOpenCL, libOpenCL.so - OCL-ICD implementation of OpenCL ICD loaderDESCRIPTION
libOpenCL.so is the library linked by OpenCL programs. It does not contains any OpenCL implementation itself, but merely act as a dispatcher to real OpenCL implementations provided as OpenCL Installable Client Driver (ICD). An ICD loader should be able to load ICDs provided by any vendors.ENVIRONMENT
Some environment variables can be used modify the default behavior of libOpenCL. OPENCL_VENDOR_PATHThis variable allows one to modify the default
/etc/OpenCL/vendors path. It is compatible with some other ICD loaders
(but not all of them, as the variable is not part of the standard). Note that
$OCL_ICD_VENDORS (see below) is used in priority if defined and not
empty.
OCL_ICD_VENDORS
This variable allows one to change the way ICD
are searched on the system. Several cases are considered:
OPENCL_LAYERS
1.if $OCL_ICD_VENDORS is a directory
path, then this path replaces the "/etc/OpenCL/vendors" path in the
standard behavior: the loader will use the .icd files in this
directory;
2.else, if $OCL_ICD_VENDORS ends with
.icd, libOpenCL.so will only load the ICD whose shared library name is
wrote into the specified ".icd" file;
If there is no slashes into $OCL_ICD_VENDORS, libOpenCL.so will first try
to use /etc/OpenCL/vendors/$OCL_ICD_VENDORS (or
$OPENCL_VENDOR_PATH /$OCL_ICD_VENDORS if
OPENCL_VENDOR_PATH is defined). If this fail or if there are shashes,
it uses $OCL_ICD_VENDORS (as a relative or absolute file name
path).
3.else libOpenCL.so will try to load
$OCL_ICD_VENDORS as the ICD shared library itself (i.e. to load it
directly with dlopen(3)).
This variable allows one to specify a colon
separated list of layers to load, specifying their path. This support is
experimental.
OCL_ICD_ASSUME_ICD_EXTENSION
If set to an non-empty value, contrary the
Khronos specification, the loader will not check that the loaded ICDs declare
the cl_khr_icd extension. It will also use the clGetPlatformInfo from the
dispatch table if no such function is globally available. You may need to
define this environment variable if you are using not (fully) compliant ICD,
or if you are using the Intel ICD together with optirun(1). In the
latter case, a bug into the Intel ICD will make the application crash.
Allows one to choose the way platforms are
sorted when presented to programs through clGetPlatformIDs(3). Current
provided algorithms are:
OCL_ICD_DEFAULT_PLATFORM
•devices: first, list platforms
that support most GPU, then most CPU then most accelerators. If
OCL_ICD_PLATFORM_SORT is not set or set to an unknown value, this
algorithm is used.
•none: no sort is done and the
order can change at each run.
Number of the platform to choose as default
platform. Note that using this environment variable without ensuring the use
of a sort algorithm for platforms is not really useful.
OCL_ICD_DEBUG
If ocl-icd has been compiled with debug
support, you can set this environment variable to a value where each bit
display some kind of informations. Defined values are:
OCL_ICD_DEBUG is mainly useful for ocl-icd development itself and/or for
ICD development.
•1: warnings (enabled by default
if debug support is present and OCL_ICD_DEBUG is not set)
•2: informative messages
•4: entering/exiting for some
OpenCL functions
•8: dump of the internal
structure of loaded ICDs
SEE ALSO
Khronos OpenCL registry websiteAUTHOR
Vincent Danjean <[email protected]>Author.
| 2015-06-08 |