path: root/static/netbsd/man9/kcpuset.9

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.Dd July 17, 2013
.Dt KCPUSET 9
.Os
.Sh NAME
.Nm kcpuset ,
.Nm kcpuset_create ,
.Nm kcpuset_destroy ,
.Nm kcpuset_clone ,
.Nm kcpuset_copy ,
.Nm kcpuset_use ,
.Nm kcpuset_unuse ,
.Nm kcpuset_copyin ,
.Nm kcpuset_copyout ,
.Nm kcpuset_zero ,
.Nm kcpuset_fill ,
.Nm kcpuset_set ,
.Nm kcpuset_clear ,
.Nm kcpuset_isset ,
.Nm kcpuset_isotherset ,
.Nm kcpuset_iszero ,
.Nm kcpuset_match ,
.Nm kcpuset_intersect ,
.Nm kcpuset_merge ,
.Nm kcpuset_remove ,
.Nm kcpuset_ffs ,
.Nm kcpuset_ffs_intersecting ,
.Nm kcpuset_countset ,
.Nm kcpuset_atomic_set ,
.Nm kcpuset_atomic_clear ,
.Nm kcpuset_atomicly_intersect ,
.Nm kcpuset_atomicly_merge ,
.Nm kcpuset_atomicly_remove ,
.Nm kcpuset_export_32
.Nd dynamic kernel CPU sets
.Sh SYNOPSIS
.In sys/kcpuset.h
.Ft void
.Fn kcpuset_create "kcpuset_t **retkcp" "bool zero"
.Ft void
.Fn kcpuset_destroy "kcpuset_t *kcp"
.Ft void
.Fn kcpuset_clone "kcpuset_t **retkcp" "const kcpuset_t *skcp"
.Ft void
.Fn kcpuset_copy "kcpuset_t *dkcp" "const kcpuset_t *skcp"
.Ft void
.Fn kcpuset_use "kcpuset_t *kcp"
.Ft void
.Fn kcpuset_unuse "kcpuset_t *kcp" "kcpuset_t **lst"
.Ft int
.Fn kcpuset_copyin "const cpuset_t *ucp" "kcpuset_t *kcp" "size_t len"
.Ft int
.Fn kcpuset_copyout "kcpuset_t *kcp" "cpuset_t *ucp" "size_t len"
.Ft void
.Fn kcpuset_zero "kcpuset_t *kcp"
.Ft void
.Fn kcpuset_fill "kcpuset_t *kcp"
.Ft void
.Fn kcpuset_set "kcpuset_t *kcp" "cpuid_t cpu"
.Ft void
.Fn kcpuset_clear "kcpuset_t *kcp" "cpuid_t cpu"
.Ft bool
.Fn kcpuset_isset "const kcpuset_t * kcp" "cpuid_t cpu"
.Ft bool
.Fn kcpuset_isotherset "const kcpuset_t * kcp" "cpuid_t cpu"
.Ft bool
.Fn kcpuset_iszero "const kcpuset_t *kcp"
.Ft bool
.Fn kcpuset_intersecting_p "const kcpuset_t *kcp1" "const kcpuset_t *kcp2"
.Ft bool
.Fn kcpuset_match "const kcpuset_t *kcp1" "const kcpuset_t *kcp2"
.Ft void
.Fn kcpuset_intersect "kcpuset_t *kcp1" "const kcpuset_t *kcp2"
.Ft void
.Fn kcpuset_merge "kcpuset_t *kcp1" "const kcpuset_t *kcp2"
.Ft void
.Fn kcpuset_remove "kcpuset_t *kcp1" "const kcpuset_t *kcp2"
.Ft cpuid_t
.Fn kcpuset_ffs "const kcpuset_t *kcp"
.Ft cpuid_t
.Fn kcpuset_ffs_intersecting "const kcpuset_t *kcp1" "const kcpuset_t *kcp2"
.Ft int
.Fn kcpuset_countset "const kcpuset_t *kcp"
.Ft void
.Fn kcpuset_atomic_set "kcpuset_t *kcp" "cpuid_t cpu"
.Ft void
.Fn kcpuset_atomic_clear "kcpuset_t *kcp" "cpuid_t cpu"
.Ft void
.Fn kcpuset_atomicly_intersect "kcpuset_t *kcp1" "const kcpuset_t *kcp2"
.Ft void
.Fn kcpuset_atomicly_merge "kcpuset_t *kcp1" "const kcpuset_t *kcp2"
.Ft void
.Fn kcpuset_atomicly_remove "kcpuset_t *kcp1" "const kcpuset_t *kcp2"
.Ft void
.Fn kcpuset_export_u32 "const kcpuset_t *kcp" "uint32_t *bitfield" "size_t len"
.Sh DESCRIPTION
The machine-independent
.Nm
subsystem provides support for dynamic processor sets.
Conceptually
.Nm
can be understood to be the kernel equivalent of the user space
.Xr cpuset 3
interface.
.Sh FUNCTIONS
.Bl -tag -width compact
.It Fn kcpuset_create "retkcp" "zero"
The
.Fn kcpuset_create
function creates a dynamic
.Tn CPU
set and stores the result to
.Fa retkcp .
If the boolean
.Fa zero
is not false, the allocated set is also initialized to zero.
.It Fn kcpuset_destroy "kcp"
Destroys the
.Tn CPU
set
.Fa kcp
and schedules any linked CPU sets for deferred destruction.
.It Fn kcpuset_copy "dkcp" "skcp"
Copies the
.Tn CPU
set pointed by
.Fa skcp
to
.Fa dkcp .
.It Fn kcpuset_clone "retkcp" "skcp"
Creates a dynamic
.Tn CPU
set and stores the result to
.Fa retkcp
and copies the
.Tn CPU
set pointed by
.Fa skcp
to the new
.Tn CPU
set.
.It Fn kcpuset_use "kcp"
Marks
.Fa kcp
as being in use by increasing the reference count of the object.
Note that initially
.Fn kcpuset_create
sets the reference count to 1.
.It Fn kcpuset_unuse "kcp" "lst"
Decreases the internal reference count of
.Fa kcp ,
and on the last reference (when the count reaches zero), destroys
.Fa kcp .
If
.Fa lst
is not
.Dv NULL ,
then instead of destroying,
.Fa kcp
will be added to the
.Fa lst
list for a deferred destruction.
.It Fn kcpuset_copyin "ucp" "kcp" "len"
Copies the
.Fa len
bytes long user-space
.Tn CPU
set
.Fa ucp
to the kernel
.Tn CPU
set
.Fa kcp .
.It Fn kcpuset_copyout "kcp" "ucp" "len"
Copies the kernel
.Tn CPU
set
.Fa kcp
to the user-space
.Tn CPU
set
.Fa ucp .
.It Fn kcpuset_zero "kcp"
Clears the set
.Fa kcp .
.It Fn kcpuset_fill "kcp"
Fills the whole set
.Fa kcp
with ones.
.It Fn kcpuset_set "kcp" "cpu"
Adds
.Fa cpu
to the set
.Fa kcp .
.It Fn kcpuset_clear "kcp" "cpu"
Removes
.Fa cpu
from the set
.Fa kcp .
.It Fn kcpuset_isset "kcp" "cpu"
Returns true if
.Fa cpu
is part of the
.Tn CPU
set
.Fa kcp .
.It Fn kcpuset_isotherset "kcp" "cpu"
Returns true if there any CPUs
other than
.Fa cpu
in the
.Tn CPU
set
.Fa kcp .
.It Fn kcpuset_iszero "kcp"
Returns true if the set
.Fa kcp
is empty.
.It Fn kcpuset_match "kcp1" "kcp2"
Compares the sets
.Fa kcp1
and
.Fa kcp2 ,
returning true if these are identical.
.It Fn kcpuset_intersect "kcp1" "kcp2"
Removes any
.Tn CPU
not set in
.Fa kcp2
from the set
.Fa kcp1 .
.It Fn kcpuset_merge "kcp1" "kcp2"
Merges the set
.Fa kcp2
to the set
.Fa kcp1 .
.It Fn kcpuset_remove "kcp1" "kcp2"
Removes any
.Tn CPU
present in
.Fa kcp2
from the set
.Fa kcp1 .
.It Fn kcpuset_ffs "kcp"
Returns the lowest numbered
.Ft cpu
present in
.Fa kcp
plus 1.
If
.Fa kcp
is empty, a value of 0 is returned.
.Fa kcp
.It Fn kcpuset_ffs_intersecting "kcp1" "kcp2"
Returns the lowest numbered
.Ft cpu
present in the intersection of
.Fa kcp1
and
.Fa kcp2
plus 1.
If the intersection is empty, a value of 0 is returned.
.It Fn kcpuset_countset "kcp"
Counts how many CPUs are in the set
.Fa kcp .
.It Fn kcpuset_atomic_set "kcp" "cpu"
The
.Fn kcpuset_atomic_set
function operates as
.Fn kcpuset_set ,
but the operation is atomic; see
.Xr atomic_ops 3
for more details.
.It Fn kcpuset_atomic_clear "kcp" "cpu"
Removes
.Fa cpu
from the
.Tn CPU
set
.Fa kcp
atomically.
.It Fn kcpuset_atomicly_intersect "kcp1" "kcp2"
The
.Fn kcpuset_atomicly_intersect
function operates as
.Fn kcpuset_intersect ,
but the operation is performed using atomic operations; see
.Xr atomic_ops 3
for more details.
.It Fn kcpuset_atomicly_merge "kcp1" "kcp2"
The
.Fn kcpuset_atomicly_merge
function operates as
.Fn kcpuset_merge ,
but the operation is performed using atomic operations; see
.Xr atomic_ops 3
for more details.
.It Fn kcpuset_atomicly_remove "kcp1" "kcp2"
The
.Fn kcpuset_atomicly_remove
function operates as
.Fn kcpuset_remove ,
but the operation is performed using atomic operations; see
.Xr atomic_ops 3
for more details.
.It Fn kcpuset_export_u32 "kcp" "bitfield" "len"
Exports the CPU set
.Fa kcp
into a format of 32-bit integer array,
specified by
.Fa bitfield
and length in bytes by
.Fa len .
An integers is in the host byte-order and represents a bit field.
The first bit at index zero represents CPU number 0, and so on.
.El
.Sh CODE REFERENCES
The
.Nm
subsystem is implemented within
.Pa sys/kern/subr_kcpuset.c .
.Sh SEE ALSO
.Xr cpuset 3
.Sh HISTORY
The
.Nm
subsystem first appeared in
.Nx 6.0 .