.TH "hwlocality_distances" 3 "Fri Apr 28 2017" "Version 1.11.7" "Hardware Locality (hwloc)" \" -*- nroff -*-
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.SH NAME
hwlocality_distances
.SH SYNOPSIS
.br
.PP
.SS "Functions"

.in +1c
.ti -1c
.RI "static const struct \fBhwloc_distances_s\fP * \fBhwloc_get_whole_distance_matrix_by_depth\fP (\fBhwloc_topology_t\fP topology, unsigned depth)"
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.ti -1c
.RI "static const struct \fBhwloc_distances_s\fP * \fBhwloc_get_whole_distance_matrix_by_type\fP (\fBhwloc_topology_t\fP topology, \fBhwloc_obj_type_t\fP type)"
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.ti -1c
.RI "static const struct \fBhwloc_distances_s\fP * \fBhwloc_get_distance_matrix_covering_obj_by_depth\fP (\fBhwloc_topology_t\fP topology, \fBhwloc_obj_t\fP obj, unsigned depth, unsigned *firstp)"
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.ti -1c
.RI "static int \fBhwloc_get_latency\fP (\fBhwloc_topology_t\fP topology, \fBhwloc_obj_t\fP obj1, \fBhwloc_obj_t\fP obj2, float *latency, float *reverse_latency)"
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.in -1c
.SH "Detailed Description"
.PP 

.SH "Function Documentation"
.PP 
.SS "static const struct \fBhwloc_distances_s\fP* hwloc_get_distance_matrix_covering_obj_by_depth (\fBhwloc_topology_t\fP topology, \fBhwloc_obj_t\fP obj, unsigned depth, unsigned * firstp)\fC [static]\fP"

.PP
Get distances for the given depth and covering some objects\&. Return a distance matrix that describes depth \fCdepth\fP and covers at least object \fCobj\fP and all its children\&.
.PP
When looking for the distance between some objects, a common ancestor should be passed in \fCobj\fP\&.
.PP
\fCfirstp\fP is set to logical index of the first object described by the matrix\&.
.PP
The returned structure belongs to the hwloc library\&. The caller should not modify or free it\&. 
.SS "static int hwloc_get_latency (\fBhwloc_topology_t\fP topology, \fBhwloc_obj_t\fP obj1, \fBhwloc_obj_t\fP obj2, float * latency, float * reverse_latency)\fC [inline]\fP, \fC [static]\fP"

.PP
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\&.
.PP
\fClatency\fP gets the value from object \fCobj1\fP to \fCobj2\fP, while \fCreverse_latency\fP gets the reverse-direction value, which may be different on some architectures\&.
.PP
\fBReturns:\fP
.RS 4
-1 if no ancestor contains a matching latency matrix\&. 
.RE
.PP

.SS "static const struct \fBhwloc_distances_s\fP* hwloc_get_whole_distance_matrix_by_depth (\fBhwloc_topology_t\fP topology, unsigned depth)\fC [static]\fP"

.PP
Get the distances between all objects at the given depth\&. 
.PP
\fBReturns:\fP
.RS 4
a distances structure containing a matrix with all distances between all objects at the given depth\&.
.RE
.PP
Slot i+nbobjs*j contains the distance from the object of logical index i the object of logical index j\&.
.PP
\fBNote:\fP
.RS 4
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\&.
.RE
.PP
The returned structure belongs to the hwloc library\&. The caller should not modify or free it\&.
.PP
\fBReturns:\fP
.RS 4
\fCNULL\fP if no such distance matrix exists\&. 
.RE
.PP

.SS "static const struct \fBhwloc_distances_s\fP* hwloc_get_whole_distance_matrix_by_type (\fBhwloc_topology_t\fP topology, \fBhwloc_obj_type_t\fP type)\fC [static]\fP"

.PP
Get the distances between all objects of a given type\&. 
.PP
\fBReturns:\fP
.RS 4
a distances structure containing a matrix with all distances between all objects of the given type\&.
.RE
.PP
Slot i+nbobjs*j contains the distance from the object of logical index i the object of logical index j\&.
.PP
\fBNote:\fP
.RS 4
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\&.
.RE
.PP
The returned structure belongs to the hwloc library\&. The caller should not modify or free it\&.
.PP
\fBReturns:\fP
.RS 4
\fCNULL\fP if no such distance matrix exists\&. 
.RE
.PP

.SH "Author"
.PP 
Generated automatically by Doxygen for Hardware Locality (hwloc) from the source code\&.