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Portable Hardware Locality (hwloc) Documentation: v1.7

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Distances

Functions

static inline struct
hwloc_distances_s
hwloc_get_whole_distance_matrix_by_depth (hwloc_topology_t topology, unsigned depth)
 
static inline struct
hwloc_distances_s
hwloc_get_whole_distance_matrix_by_type (hwloc_topology_t topology, hwloc_obj_type_t type)
 
static inline struct
hwloc_distances_s
hwloc_get_distance_matrix_covering_obj_by_depth (hwloc_topology_t topology, hwloc_obj_t obj, unsigned depth, unsigned *firstp)
 
static inline int hwloc_get_latency (hwloc_topology_t topology, hwloc_obj_t obj1, hwloc_obj_t obj2, float *latency, float *reverse_latency)
 

Detailed Description

Function Documentation

static inline struct hwloc_distances_s* hwloc_get_distance_matrix_covering_obj_by_depth ( hwloc_topology_t  topology,
hwloc_obj_t  obj,
unsigned  depth,
unsigned *  firstp 
)
staticread

Get distances for the given depth and covering some objects.

Return a distance matrix that describes depth depth and covers at least object obj and all its children.

When looking for the distance between some objects, a common ancestor should be passed in obj.

firstp is set to logical index of the first object described by the matrix.

The returned structure belongs to the hwloc library. The caller should not modify or free it.

static inline int hwloc_get_latency ( hwloc_topology_t  topology,
hwloc_obj_t  obj1,
hwloc_obj_t  obj2,
float *  latency,
float *  reverse_latency 
)
static

Get the latency in both directions between two objects.

Look at ancestor objects from the bottom to the top until one of them contains a distance matrix that matches the objects exactly.

latency gets the value from object obj1 to obj2, while reverse_latency gets the reverse-direction value, which may be different on some architectures.

Returns
-1 if no ancestor contains a matching latency matrix.
static inline struct hwloc_distances_s* hwloc_get_whole_distance_matrix_by_depth ( hwloc_topology_t  topology,
unsigned  depth 
)
staticread

Get the distances between all objects at the given depth.

Returns
a distances structure containing a matrix with all distances between all objects at the given depth.

Slot i+nbobjs*j contains the distance from the object of logical index i the object of logical index j.

Note
This function only returns matrices covering the whole topology, without any unknown distance value. Those matrices are available in top-level object of the hierarchy. Matrices of lower objects are not reported here since they cover only part of the machine.

The returned structure belongs to the hwloc library. The caller should not modify or free it.

Returns
NULL if no such distance matrix exists.
static inline struct hwloc_distances_s* hwloc_get_whole_distance_matrix_by_type ( hwloc_topology_t  topology,
hwloc_obj_type_t  type 
)
staticread

Get the distances between all objects of a given type.

Returns
a distances structure containing a matrix with all distances between all objects of the given type.

Slot i+nbobjs*j contains the distance from the object of logical index i the object of logical index j.

Note
This function only returns matrices covering the whole topology, without any unknown distance value. Those matrices are available in top-level object of the hierarchy. Matrices of lower objects are not reported here since they cover only part of the machine.

The returned structure belongs to the hwloc library. The caller should not modify or free it.

Returns
NULL if no such distance matrix exists.