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Portable Hardware Locality (hwloc) Documentation: v0.9.1

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Configure Topology Detection

Enumerations

enum  hwloc_topology_flags_e { HWLOC_TOPOLOGY_FLAG_WHOLE_SYSTEM = (1<<0), HWLOC_TOPOLOGY_FLAG_IS_THISSYSTEM = (1<<1) }
 

Flags to be set onto a topology context before load.

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Functions

int hwloc_topology_ignore_type (hwloc_topology_t topology, hwloc_obj_type_t type)
 Ignore an object type.
int hwloc_topology_ignore_type_keep_structure (hwloc_topology_t topology, hwloc_obj_type_t type)
 Ignore an object type if it does not bring any structure.
int hwloc_topology_ignore_all_keep_structure (hwloc_topology_t topology)
 Ignore all objects that do not bring any structure.
int hwloc_topology_set_flags (hwloc_topology_t topology, unsigned long flags)
 Set OR'ed flags to non-yet-loaded topology.
int hwloc_topology_set_fsroot (hwloc_topology_t restrict topology, const char *restrict fsroot_path)
 Change the file-system root path when building the topology from sysfs/procfs.
int hwloc_topology_set_synthetic (hwloc_topology_t restrict topology, const char *restrict description)
 Enable synthetic topology.
int hwloc_topology_set_xml (hwloc_topology_t restrict topology, const char *restrict xmlpath)
 Enable XML-file based topology.

Detailed Description

These functions can optionally be called between hwloc_topology_init() and hwloc_topology_load() to configure how the detection should be performed, e.g. to ignore some objects types, define a synthetic topology, etc.

If none of them is called, the default is to detect all the objects of the machine that the caller is allowed to access.

This default behavior may also be modified through environment variables if the application did not modify it already. Setting HWLOC_XMLFILE in the environment enforces the discovery from a XML file as if hwloc_topology_set_xml() had been called. HWLOC_FSROOT switches to reading the topology from the specified Linux filesystem root as if hwloc_topology_set_fsroot() had been called. Finally, HWLOC_THISSYSTEM enforces the value of the is_thissystem field.


Enumeration Type Documentation

Flags to be set onto a topology context before load.

Flags should be given to hwloc_topology_set_flags().

Enumerator:
HWLOC_TOPOLOGY_FLAG_WHOLE_SYSTEM 
HWLOC_TOPOLOGY_FLAG_IS_THISSYSTEM 

Function Documentation

int hwloc_topology_ignore_all_keep_structure ( hwloc_topology_t  topology  ) 

Ignore all objects that do not bring any structure.

Ignore all objects that do not bring any structure: Each ignored object should have a single children or be the only child of its father.

int hwloc_topology_ignore_type ( hwloc_topology_t  topology,
hwloc_obj_type_t  type 
)

Ignore an object type.

Ignore all objects from the given type. The top-level type HWLOC_OBJ_SYSTEM and bottom-level type HWLOC_OBJ_PROC may not be ignored.

int hwloc_topology_ignore_type_keep_structure ( hwloc_topology_t  topology,
hwloc_obj_type_t  type 
)

Ignore an object type if it does not bring any structure.

Ignore all objects from the given type as long as they do not bring any structure: Each ignored object should have a single children or be the only child of its father. The top-level type HWLOC_OBJ_SYSTEM and bottom-level type HWLOC_OBJ_PROC may not be ignored.

int hwloc_topology_set_flags ( hwloc_topology_t  topology,
unsigned long  flags 
)

Set OR'ed flags to non-yet-loaded topology.

Set a OR'ed set of hwloc_topology_flags_e onto a topology that was not yet loaded.

int hwloc_topology_set_fsroot ( hwloc_topology_t restrict  topology,
const char *restrict  fsroot_path 
)

Change the file-system root path when building the topology from sysfs/procfs.

On Linux system, use sysfs and procfs files as if they were mounted on the given fsroot_path instead of the main file-system root. Setting the environment variable HWLOC_FSROOT may also result in this behavior. Not using the main file-system root causes hwloc_topology_is_thissystem field to return 0.

Note:
For conveniency, this backend provides empty binding hooks which just return success. To have hwloc still actually call OS-specific hooks, the HWLOC_TOPOLOGY_FLAG_IS_THISSYSTEM has to be set to assert that the loaded file is really the underlying system.
int hwloc_topology_set_synthetic ( hwloc_topology_t restrict  topology,
const char *restrict  description 
)

Enable synthetic topology.

Gather topology information from the given description which should be a comma separated string of numbers describing the arity of each level. Each number may be prefixed with a type and a colon to enforce the type of a level.

Note:
For conveniency, this backend provides empty binding hooks which just return success.
int hwloc_topology_set_xml ( hwloc_topology_t restrict  topology,
const char *restrict  xmlpath 
)

Enable XML-file based topology.

Gather topology information the XML file given at xmlpath. Setting the environment variable HWLOC_XMLFILE may also result in this behavior. This file may have been generated earlier with lstopo file.xml.

Note:
For conveniency, this backend provides empty binding hooks which just return success. To have hwloc still actually call OS-specific hooks, the HWLOC_TOPOLOGY_FLAG_IS_THISSYSTEM has to be set to assert that the loaded file is really the underlying system.