NAME

     cpuset(9) — CPUSET_T_INITIALIZER, CPUSET_FSET, CPU_CLR, CPU_COPY, CPU_ISSET, CPU_SET, CPU_ZERO, CPU_FILL,
     CPU_SETOF, CPU_EMPTY, CPU_ISFULLSET, CPU_FFS, CPU_COUNT, CPU_SUBSET, CPU_OVERLAP, CPU_CMP, CPU_OR, CPU_AND,
     CPU_NAND, CPU_CLR_ATOMIC, CPU_SET_ATOMIC, CPU_SET_ATOMIC_ACQ, CPU_AND_ATOMIC, CPU_OR_ATOMIC,
     CPU_COPY_STORE_REL — cpuset manipulation macros

SYNOPSIS

     #include <sys/_cpuset.h>
     #include <sys/cpuset.h>

     CPUSET_T_INITIALIZER(ARRAY_CONTENTS);

     CPUSET_FSET

     CPU_CLR(size_t cpu_idx, cpuset_t *cpuset);

     CPU_COPY(cpuset_t *from, cpuset_t *to);

     bool
     CPU_ISSET(size_t cpu_idx, cpuset_t *cpuset);

     CPU_SET(size_t cpu_idx, cpuset_t *cpuset);

     CPU_ZERO(cpuset_t *cpuset);

     CPU_FILL(cpuset_t *cpuset);

     CPU_SETOF(size_t cpu_idx, cpuset_t *cpuset);

     bool
     CPU_EMPTY(cpuset_t *cpuset);

     bool
     CPU_ISFULLSET(cpuset_t *cpuset);

     int
     CPU_FFS(cpuset_t *cpuset);

     int
     CPU_COUNT(cpuset_t *cpuset);

     bool
     CPU_SUBSET(cpuset_t *haystack, cpuset_t *needle);

     bool
     CPU_OVERLAP(cpuset_t *cpuset1, cpuset_t *cpuset2);

     bool
     CPU_CMP(cpuset_t *cpuset1, cpuset_t *cpuset2);

     CPU_OR(cpuset_t *dst, cpuset_t *src);

     CPU_AND(cpuset_t *dst, cpuset_t *src);

     CPU_NAND(cpuset_t *dst, cpuset_t *src);

     CPU_CLR_ATOMIC(size_t cpu_idx, cpuset_t *cpuset);

     CPU_SET_ATOMIC(size_t cpu_idx, cpuset_t *cpuset);

     CPU_SET_ATOMIC_ACQ(size_t cpu_idx, cpuset_t *cpuset);

     CPU_AND_ATOMIC(cpuset_t *dst, cpuset_t *src);

     CPU_OR_ATOMIC(cpuset_t *dst, cpuset_t *src);

     CPU_COPY_STORE_REL(cpuset_t *from, cpuset_t *to);

DESCRIPTION

     The cpuset(9) family of macros provide a flexible and efficient CPU set implementation, backed by the
     bitset(9) macros.  Each CPU is represented by a single bit.  The maximum number of CPUs representable by
     cpuset_t is MAXCPU.  Individual CPUs in cpusets are referenced with indices zero through MAXCPU - 1.

     The CPUSET_T_INITIALIZER() macro allows one to initialize a cpuset_t with a compile time literal value.

     The CPUSET_FSET() macro defines a compile time literal, usable by CPUSET_T_INITIALIZER(), representing a
     full cpuset (all CPUs present).  For examples of CPUSET_T_INITIALIZER() and CPUSET_FSET() usage, see the
     CPUSET_T_INITIALIZER EXAMPLE section.

     The CPU_CLR() macro removes CPU cpu_idx from the cpuset pointed to by cpuset.  The CPU_CLR_ATOMIC() macro
     is identical, but the bit representing the CPU is cleared with atomic machine instructions.

     The CPU_COPY() macro copies the contents of the cpuset from to the cpuset to.  CPU_COPY_STORE_REL() is
     similar, but copies component machine words from from and writes them to to with atomic store with release
     semantics.  (That is, if to is composed of multiple machine words, CPU_COPY_STORE_REL() performs multiple
     individually atomic operations.)

     The CPU_SET() macro adds CPU cpu_idx to the cpuset pointed to by cpuset, if it is not already present.  The
     CPU_SET_ATOMIC() macro is identical, but the bit representing the CPU is set with atomic machine
     instructions.  The CPU_SET_ATOMIC_ACQ() macro sets the bit representing the CPU with atomic acquire
     semantics.

     The CPU_ZERO() macro removes all CPUs from cpuset.

     The CPU_FILL() macro adds all CPUs to cpuset.

     The CPU_SETOF() macro removes all CPUs in cpuset before adding only CPU cpu_idx.

     The CPU_EMPTY() macro returns true if cpuset is empty.

     The CPU_ISFULLSET() macro returns true if cpuset is full (the set of all CPUs).

     The CPU_FFS() macro returns the 1-index of the first (lowest) CPU in cpuset, or zero if cpuset is empty.
     Like with ffs(3), to use the non-zero result of CPU_FFS() as a cpu_idx index parameter to any other
     cpuset(9) macro, you must subtract one from the result.

     The CPU_COUNT() macro returns the total number of CPUs in cpuset.

     The CPU_SUBSET() macro returns true if needle is a subset of haystack.

     The CPU_OVERLAP() macro returns true if cpuset1 and cpuset2 have any common CPUs.  (That is, if cpuset1 AND
     cpuset2 is not the empty set.)

     The CPU_CMP() macro returns true if cpuset1 is NOT equal to cpuset2.

     The CPU_OR() macro adds CPUs present in src to dst.  (It is the cpuset(9) equivalent of the scalar: dst |=
     src.)  CPU_OR_ATOMIC() is similar, but sets the bits representing CPUs in the component machine words in
     dst with atomic machine instructions.  (That is, if dst is composed of multiple machine words,
     CPU_OR_ATOMIC() performs multiple individually atomic operations.)

     The CPU_AND() macro removes CPUs absent from src from dst.  (It is the cpuset(9) equivalent of the scalar:
     dst &= src.)  CPU_AND_ATOMIC() is similar, with the same atomic semantics as CPU_OR_ATOMIC().

     The CPU_NAND() macro removes CPUs in src from dst.  (It is the cpuset(9) equivalent of the scalar: dst &= ~
     src.)

CPUSET_T_INITIALIZER EXAMPLE

     cpuset_t myset;

     /* Initialize myset to filled (all CPUs) */
     myset = CPUSET_T_INITIALIZER(CPUSET_FSET);

     /* Initialize myset to only the lowest CPU */
     myset = CPUSET_T_INITIALIZER(0x1);

SEE ALSO

     cpuset(1), cpuset(2), bitset(9)

HISTORY

     <sys/cpuset.h> first appeared in FreeBSD 7.1, released in January 2009, and in FreeBSD 8.0, released in
     November 2009.

     This manual page first appeared in FreeBSD 11.0.

AUTHORS

     The cpuset(9) macros were written by Jeff Roberson <jeff@FreeBSD.org>.  This manual page was written by
     Conrad Meyer <cem@FreeBSD.org>.

CAVEATS

     Unlike every other reference to individual set members, which are zero-indexed, CPU_FFS() returns a one-
     indexed result (or zero if the cpuset is empty).