rad_get_num, rad_get_cpus, rad_get_freemem, rad_get_info,
rad_get_max, rad_get_physmem, rad_get_state - Query
resource complements of a Resource Affinity Domain (libnuma)
#include <numa.h>
int rad_get_cpus(
radid_t rad,
cpuset_t cpuset ); ssize_t rad_get_freemem(
radid_t rad ); int rad_get_info(
radid_t rad,
rad_info_t *info ); int rad_get_max(
void ); int rad_get_num(
void ); ssize_t rad_get_physmem(
radid_t rad ); ssize_t rad_get_state(
radid_t rad );
Specifies a buffer to receive the CPU set assigned to the
specified Resource Affinity Domain (RAD) in the caller's
partition Points to a buffer to receive information about
the specified RAD. Identifies the RAD for which the
resource complement is being requested.
A Resource Affinity Domain (RAD) is a collection of
resources that are related by the platform hardware topology.
The collection of processors and I/O buses connected
to a local memory of a NUMA platform, plus the local memory
itself, comprise a RAD. More generally, a RAD may be
characterized as a set of resources that are within some
"distance" of each other.
The rad_get_info() function stores in the buffer pointed
to by info, a rad_info_t structure containing information
about the RAD specified by the radid argument. This information
includes the state of the RAD, the amount of memory
in the RAD, and the CPUs it contains. The remaining functions
on this reference page return individual members of
the rad_info_t structure.
The rad_get_cpus() function stores in the buffer specified
by cpuset the set of CPUs in the specified RAD that are
assigned to the caller's partition.
The rad_get_freemem() function returns a snapshot of the
amount of free memory (pages) in the specified RAD in the
caller's partition.
The rad_get_max() function returns the maximum number of
RADs on the system.
The rad_get_num() function returns the number of RADs in
the caller's partition.
The rad_get_physmem() function returns the amount of physical
memory (pages) assigned to the specified RAD in the
caller's partition.
The rad_get_state() function returns the current state of
the RAD specified by the radid argument. The possible RAD
state values are: The specified RAD exists and is on line.
Processes and threads may be assigned to the RAD and memory
may be allocated there. The specified RAD exists but
is not currently on line. Neither processes nor threads
may be assigned to this RAD, and no memory may be allocated
there. However, the RAD's resource complement may be
queried.
Note
Currently, RAD state is always set to RAD_ONLINE;
therefore, consider this function as being reserved
for future use.
Note that prior to calling any of the rad_get_*() functions,
the application must set the rinfo_version field in
the rad_info_t structure to RAD_INFO_VERSION. The CPU set
(cpuset) stored in this structure must have been created
by the application prior to the call. If zero is specified
for cpuset, the function does not fill in data for the CPU
set.
As with many queries of system information, the data
returned by these functions may be stale by the time it is
returned to or used by the calling application.
The rad_get_info() and rad_get_cpus() functions return the
following values: Success. In this case, the integer value
is the number of CPUs in the specified RAD. Failure. In
this case, errno is set to indicate the error.
The rad_get_freemem() and rad_get_physmem() functions
return the following: Success. Depending on the function,
this value is the amount of free memory for the specified
RAD or the amount of physical memory assigned to the RAD.
Failure. In this case, errno is set to indicate the error.
The rad_get_num() and rad_get_max() functions return the
number of RADs in the caller's partition or on the system,
respectively. There is no value defined to indicate failure
for these functions.
The rad_get_state() function always returns a state value.
There is no value defined to indicate failure for this
function.
The rad_get_cpus(), rad_get_info(), rad_get_freemem(), and
rad_get_physmem() functions set errno to one of the following
values for the specified condition: The cpuset
argument indirectly points to an invalid address, or the
specified CPU set does not exist, possibly because it was
not created by a call to cpusetcreate(). The rad argument
specifies a RAD that does not exist. The version number
specified for the rinfo_version field in the info argument
is not recognized by the system.
The following example prints data returned by a call to
rad_get_info():
#include <sys/errno.h> #include <numa.h>
int print_rad_info(radid_t rad) {
rad_info_t radinfo;
/* Create a cpuset for the radinfo struct. */
cpusetcreate(&radinfo.rinfo_cpuset);
radinfo.rinfo_version = RAD_INFO_VERSION;
/* Fetch the data */
if (rad_get_info(rad, &radinfo) == -1) {
perror("rad_get_info");
return -1;
}
/* Simple data types can be printed directly. */
printf("rinfo_radid = %d\n", radinfo.rinfo_radid);
printf("rinfo_state = %d\n", radinfo.rinfo_state);
printf("rinfo_physmem = 0x%lx pages\n", radinfo.rinfo_physmem);
printf("rinfo_freemem = 0x%lx pages\n", radinfo.rinfo_freemem);
printf("\ncpuset members: ");
/* Complex datatypes (cpuset) need to be enumerated.
*/
while (1) {
cpuid_t id;
int flags = SET_CURSOR_CONSUME;
cpu_cursor_t cpu_cursor = SET_CURSOR_INIT;
id = cpu_foreach(radinfo.rinfo_cpuset,
flags, &cpu_cursor);
if (id == CPU_NONE) {
printf("\n");
break;
} else {
printf("%3d ", id);
}
}
/* Destroy cpuset */
cpusetdestroy(&radinfo.rinfo_cpuset);
return 0; }
Functions: cpu_foreach(3), cpusetcreate(3), nloc(3),
numa_intro(3)
Files: numa_types(4)
rad_get_num(3)
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