Looking at Ancestor and Child Objects

Functions
hwloc_obj_t	hwloc_get_ancestor_obj_by_depth (hwloc_topology_t topology, int depth, hwloc_obj_t obj)
hwloc_obj_t	hwloc_get_ancestor_obj_by_type (hwloc_topology_t topology, hwloc_obj_type_t type, hwloc_obj_t obj)
hwloc_obj_t	hwloc_get_common_ancestor_obj (hwloc_topology_t topology, hwloc_obj_t obj1, hwloc_obj_t obj2)
int	hwloc_obj_is_in_subtree (hwloc_topology_t topology, hwloc_obj_t obj, hwloc_obj_t subtree_root)
hwloc_obj_t	hwloc_get_next_child (hwloc_topology_t topology, hwloc_obj_t parent, hwloc_obj_t prev)

Detailed Description

Be sure to see the figure in Terms and Definitions that shows a complete topology tree, including depths, child/sibling/cousin relationships, and an example of an asymmetric topology where one package has fewer caches than its peers.

Function Documentation

hwloc_get_ancestor_obj_by_depth()

hwloc_obj_t hwloc_get_ancestor_obj_by_depth ( hwloc_topology_t topology, int depth, hwloc_obj_t obj )

inline

Returns the ancestor object of obj at depth depth.

Returns

the ancestor if any.

NULL if no such ancestor exists.

Note

depth should not be the depth of PU or NUMA objects since they are ancestors of no objects (except Misc or I/O). This function rather expects an intermediate level depth, such as the depth of Packages, Cores, or Caches.

hwloc_get_ancestor_obj_by_type()

hwloc_obj_t hwloc_get_ancestor_obj_by_type ( hwloc_topology_t topology, hwloc_obj_type_t type, hwloc_obj_t obj )

inline

Returns the ancestor object of obj with type type.

Returns

the ancestor if any.

NULL if no such ancestor exists.

Note

if multiple matching ancestors exist (e.g. multiple levels of HWLOC_OBJ_GROUP) the lowest one is returned.

type should not be HWLOC_OBJ_PU or HWLOC_OBJ_NUMANODE since these objects are ancestors of no objects (except Misc or I/O). This function rather expects an intermediate object type, such as HWLOC_OBJ_PACKAGE, HWLOC_OBJ_CORE, etc.

hwloc_get_common_ancestor_obj()

hwloc_obj_t hwloc_get_common_ancestor_obj ( hwloc_topology_t topology, hwloc_obj_t obj1, hwloc_obj_t obj2 )

inline

Returns the common parent object to objects obj1 and obj2.

Returns

the common ancestor.

Note

This function cannot return NULL.

hwloc_get_next_child()

hwloc_obj_t hwloc_get_next_child ( hwloc_topology_t topology, hwloc_obj_t parent, hwloc_obj_t prev )

inline

Return the next child.

Return the next child among the normal children list, then among the memory children list, then among the I/O children list, then among the Misc children list.

Returns

the first child if prev is NULL.

the next child if prev is not NULL.

NULL when there is no next child.

hwloc_obj_is_in_subtree()

int hwloc_obj_is_in_subtree ( hwloc_topology_t topology, hwloc_obj_t obj, hwloc_obj_t subtree_root )

inline

Returns true if obj is inside the subtree beginning with ancestor object subtree_root.

Returns

1 is the object is in the subtree, 0 otherwise.

Note

This function cannot work if obj and subtree_root objects do not have CPU sets (I/O or Misc objects).