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Portable Hardware Locality (hwloc) Documentation: v2.10.0

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Interoperability with OpenCL

Functions

static int hwloc_opencl_get_device_pci_busid (cl_device_id device, unsigned *domain, unsigned *bus, unsigned *dev, unsigned *func)
 
static int hwloc_opencl_get_device_cpuset (hwloc_topology_t topology, cl_device_id device, hwloc_cpuset_t set)
 
static hwloc_obj_t hwloc_opencl_get_device_osdev_by_index (hwloc_topology_t topology, unsigned platform_index, unsigned device_index)
 
static hwloc_obj_t hwloc_opencl_get_device_osdev (hwloc_topology_t topology, cl_device_id device)
 

Detailed Description

This interface offers ways to retrieve topology information about OpenCL devices.

Only AMD and NVIDIA OpenCL implementations currently offer useful locality information about their devices.

Function Documentation

◆ hwloc_opencl_get_device_cpuset()

static int hwloc_opencl_get_device_cpuset ( hwloc_topology_t  topology,
cl_device_id  device,
hwloc_cpuset_t  set 
)
inlinestatic

Get the CPU set of processors that are physically close to OpenCL device device.

Store in set the CPU-set describing the locality of the OpenCL device device.

Topology topology and device device must match the local machine. I/O devices detection and the OpenCL component are not needed in the topology.

The function only returns the locality of the device. If more information about the device is needed, OS objects should be used instead, see hwloc_opencl_get_device_osdev() and hwloc_opencl_get_device_osdev_by_index().

This function is currently only implemented in a meaningful way for Linux with the AMD or NVIDIA OpenCL implementation; other systems will simply get a full cpuset.

Returns
0 on success.
-1 on error, for instance if the device could not be found.

◆ hwloc_opencl_get_device_osdev()

static hwloc_obj_t hwloc_opencl_get_device_osdev ( hwloc_topology_t  topology,
cl_device_id  device 
)
inlinestatic

Get the hwloc OS device object corresponding to OpenCL device deviceX.

Returns
The hwloc OS device object corresponding to the given OpenCL device device.
NULL if none could be found, for instance if required OpenCL attributes are not available.

This function currently only works on AMD and NVIDIA OpenCL devices that support relevant OpenCL extensions. hwloc_opencl_get_device_osdev_by_index() should be preferred whenever possible, i.e. when platform and device index are known.

Topology topology and device device must match the local machine. I/O devices detection and the OpenCL component must be enabled in the topology. If not, the locality of the object may still be found using hwloc_opencl_get_device_cpuset().

Note
This function cannot work if PCI devices are filtered out.
The corresponding hwloc PCI device may be found by looking at the result parent pointer (unless PCI devices are filtered out).

◆ hwloc_opencl_get_device_osdev_by_index()

static hwloc_obj_t hwloc_opencl_get_device_osdev_by_index ( hwloc_topology_t  topology,
unsigned  platform_index,
unsigned  device_index 
)
inlinestatic

Get the hwloc OS device object corresponding to the OpenCL device for the given indexes.

Returns
The hwloc OS device object describing the OpenCL device whose platform index is platform_index, and whose device index within this platform if device_index.
NULL if there is none.

The topology topology does not necessarily have to match the current machine. For instance the topology may be an XML import of a remote host. I/O devices detection and the OpenCL component must be enabled in the topology.

Note
The corresponding PCI device object can be obtained by looking at the OS device parent object (unless PCI devices are filtered out).

◆ hwloc_opencl_get_device_pci_busid()

static int hwloc_opencl_get_device_pci_busid ( cl_device_id  device,
unsigned *  domain,
unsigned *  bus,
unsigned *  dev,
unsigned *  func 
)
inlinestatic

Return the domain, bus and device IDs of the OpenCL device device.

Device device must match the local machine.

Returns
0 on success.
-1 on error, for instance if device information could not be found.