cpusetops(3)cpusetops(3)NAME
cpusetops, cpuaddset, cpuandset, cpucopyset, cpucountset, cpudelset,
cpudiffset, cpuemptyset, cpufillset, cpuisemptyset, cpuismember,
cpuorset, cpusetcreate, cpusetdestroy, cpuxorset - Perform operations
on CPU sets (libc library)
SYNOPSIS
#include <cpuset.h>
int cpuaddset(
cpuset_t set,
cpuid_t cpuid ); int cpuandset(
cpuset_t set_src1,
cpuset_t set_src2,
cpuset_t set_dst ); int cpucopyset(
cpuset_t set_src,
cpuset_t set_dst ); int cpucountset(
cpuset_t set ); int cpudelset(
cpuset_t set,
cpuid_t cpuid ); int cpudiffset(
cpuset_t set_src1,
cpuset_t set_src2,
cpuset_t set_dst ); int cpuemptyset(
cpuset_t set ); int cpufillset(
cpuset_t set ); int cpuisemptyset(
cpuset_t set ); int cpuismember(
cpuset_t set,
cpuid_t cpuid ); int cpuorset(
cpuset_t set_src1,
cpuset_t set_src2,
cpuset_t set_dst ); int cpusetcreate(
cpuset_t *set ); int cpusetdestroy(
cpuset_t *set ); int cpuxorset(
cpuset_t set_src1,
cpuset_t set_src2,
cpuset_t set_dst );
PARAMETERS
Identifies a CPU. Specifies or points to a CPU set. Specifies a CPU
set that is being copied to or that is the result of a logical OR, XOR,
or AND operation on two other CPU sets. Specifies a CPU set that is
being copied to another CPU set or that is part of a logical OR, XOR,
or AND operation with another CPU set.
DESCRIPTION
The cpusetops primitives manipulate sets of CPUs, by operating on data
objects (of type cpuset_t) that are created by cpusetcreate().
The cpusetcreate() function allocates, and sets to empty, a CPU set
pointed to by set.
The cpusetdestroy() function releases the memory that was obtained by
cpusetcreate() for the specified CPU set pointed to by set.
The cpucountset() function returns the number of members in the CPU set
specified by set.
The cpuemptyset() function initializes the CPU set specified by set,
such that no CPUs are included in the set.
The cpufillset() function initializes the CPU set specified by set,
such that as many CPUs as the system architecture is capable of sup‐
porting are included in the set. Note that this platform maximum might
be more than the number of CPUs that are available on the system.
The cpuismember() function tests whether the CPU specified by the value
of cpuid is a member of the CPU set specified by set.
The cpuisemptyset() function tests whether the CPU set specified by the
set is empty.
The cpucopyset() function copies the contents of the CPU set specified
by set_src to the CPU set specified by set_dst.
The cpuaddset() and cpudelset() functions respectively add or delete
the individual CPU specified by the value of cpuid to or from the CPU
set specified by set.
The cpuandset(), cpuorset(), and cpuxorset() functions perform a logi‐
cal AND, OR, or XOR operation, respectively, on the CPU sets specified
by set_src1 and set_src2, storing the result in the CPU set specified
by set_dst.
The cpudiffset() function finds the logical difference between the CPU
sets specified by set_src1 and set_src2, storing the result in the CPU
set specified by set_dst. (The result is made up of members that are
included in set_src1 but not in
set_src2.)
RETURN VALUES
These functions return the following values: Success (returned by all
functions).
For cpuisemptyset() and cpuismember() only, 0 also means the
condition being tested is false; that is, the specified CPU set
is not empty or does not contain the specified member. Success
(returned by cpuisemptyset() and cpuismember()only). This
return value also means the condition being tested is true; that
is, the specified CPU set is empty or contains the specified
member. Failure (returned by all functions). In this case,
errno is set to indicate the error.
ERRORS
The cpuaddset(), cpuandset(), cpucopyset(), cpucountset(), cpudelset(),
cpudiffset(), cpuemptyset(), cpufillset(), cpuisemptyset(), cpuismem‐
ber(), cpuorset(), and cpuxorset() functions set errno to the following
value for the corresponding condition: The value of a set or set_*
argument is invalid (possibly is not a CPU set created bycpusetcre‐
ate()).
The cpusetcreate() and cpusetdestroy() functions set errno to one of
the the following values for the corresponding condition: The address
of the specified CPU set is invalid. For cpusetcreate() only, no mem‐
ory could be allocated for the specified CPU set.
If the cpuaddset(), cpudelset(), and cpuismember() functions fail, they
set errno to the following value for the reason specified: The value of
cpuid is an invalid or unsupported CPU identifier.
EXAMPLES
The following example demonstrates a variety of CPU set operations:
#include <cpuset.h>
int main() {
cpuset_t cpuset, cpuset2;
/* Create cpusets - initialized as empty */
cpusetcreate(&cpuset);
cpusetcreate(&cpuset2);
/* demonstrate cpuset operations */
/* add cpu 0 to cpuset */
if (cpuaddset(cpuset, 0) == -1) {
perror("cpuaddset");
return 0;
}
/* copy cpuset to cpuset2 */
if (cpucopyset(cpuset, cpuset2) == -1) {
perror("cpucopyset");
return 0;
}
if (cpuaddset(cpuset, 1) == -1) {
/* add cpu 1 to cpuset */
perror("cpuaddset");
return 0;
}
/* difference of cpuset and cpuset2, store in cpuset */
if (cpudiffset(cpuset, cpuset2, cpuset) == -1) {
perror("cpudiffset");
return 0;
}
/* Enumerate cpuset. */
while (1) {
cpuid_t id;
int flags = SET_CURSOR_CONSUME;
cpu_cursor_t cpu_cursor = SET_CURSOR_INIT;
id = cpu_foreach(cpuset, flags, &cpu_cursor);
if (id == CPU_NONE) {
printf("\n");
break;
} else {
printf("%3d ", id);
}
}
/* Destroy cpuset */
cpusetdestroy(&cpuset);
cpusetdestroy(&cpuset2);
return 0; }
SEE ALSO
Functions: cpu_foreach(3), numa_intro(3)
Files: numa_types(4)cpusetops(3)
