Hardware Locality (hwloc): Converting between CPU sets and node sets

Hardware Locality (hwloc) 1.9

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Converting between CPU sets and node sets

## Functions
static void | hwloc_cpuset_to_nodeset (hwloc_topology_t topology, hwloc_const_cpuset_t _cpuset, hwloc_nodeset_t nodeset)
static void | hwloc_cpuset_to_nodeset_strict (struct hwloc_topology *topology, hwloc_const_cpuset_t _cpuset, hwloc_nodeset_t nodeset)
static void | hwloc_cpuset_from_nodeset (hwloc_topology_t topology, hwloc_cpuset_t _cpuset, hwloc_const_nodeset_t nodeset)
static void | hwloc_cpuset_from_nodeset_strict (struct hwloc_topology *topology, hwloc_cpuset_t _cpuset, hwloc_const_nodeset_t nodeset)

## Detailed Description

There are two semantics for converting cpusets to nodesets depending on how non-NUMA machines are handled.

When manipulating nodesets for memory binding, non-NUMA machines should be considered as having a single NUMA node. The standard conversion routines below should be used so that marking the first bit of the nodeset means that memory should be bound to a non-NUMA whole machine.

When manipulating nodesets as an actual list of NUMA nodes without any need to handle memory binding on non-NUMA machines, the strict conversion routines may be used instead.

## Function Documentation

static void hwloc_cpuset_from_nodeset | ( | hwloc_topology_t | topology,
|  | hwloc_cpuset_t | _cpuset,
|  | hwloc_const_nodeset_t | nodeset
| ) |  |
| inlinestatic

Convert a NUMA node set into a CPU set and handle non-NUMA cases.

If the topology contains no NUMA nodes, the machine is considered as a single memory node, and the following behavior is used: If `nodeset` is empty, `cpuset` will be emptied as well. Otherwise `cpuset` will be entirely filled. This is useful for manipulating memory binding sets.

static void hwloc_cpuset_from_nodeset_strict | ( | struct hwloc_topology * | topology,
|  | hwloc_cpuset_t | _cpuset,
|  | hwloc_const_nodeset_t | nodeset
| ) |  |
| inlinestatic

Convert a NUMA node set into a CPU set without handling non-NUMA cases.

This is the strict variant of hwloc_cpuset_from_nodeset. It does not fix non-NUMA cases. If the topology contains some NUMA nodes, behave exactly the same. However, if the topology contains no NUMA nodes, return an empty cpuset.

static void hwloc_cpuset_to_nodeset | ( | hwloc_topology_t | topology,
|  | hwloc_const_cpuset_t | _cpuset,
|  | hwloc_nodeset_t | nodeset
| ) |  |
| inlinestatic

Convert a CPU set into a NUMA node set and handle non-NUMA cases.

If some NUMA nodes have no CPUs at all, this function never sets their indexes in the output node set, even if a full CPU set is given in input.

If the topology contains no NUMA nodes, the machine is considered as a single memory node, and the following behavior is used: If `cpuset` is empty, `nodeset` will be emptied as well. Otherwise `nodeset` will be entirely filled.

static void hwloc_cpuset_to_nodeset_strict | ( | struct hwloc_topology * | topology,
|  | hwloc_const_cpuset_t | _cpuset,
|  | hwloc_nodeset_t | nodeset
| ) |  |
| inlinestatic

Convert a CPU set into a NUMA node set without handling non-NUMA cases.

This is the strict variant of hwloc_cpuset_to_nodeset. It does not fix non-NUMA cases. If the topology contains some NUMA nodes, behave exactly the same. However, if the topology contains no NUMA nodes, return an empty nodeset.