CPUSET(9) | Kernel Developer's Manual | CPUSET(9) |
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
#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);
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 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);
<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.
The cpuset(9)
macros were written by
Jeff Roberson
<jeff@FreeBSD.org>.
This manual page was written by Conrad Meyer
<cem@FreeBSD.org>.
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).
July 29, 2016 | Debian |