KCPUSET(9)

KCPUSET(9) | NetBSD Kernel Developer's Manual | KCPUSET(9)

# NAME

kcpuset, kcpuset_create, kcpuset_destroy, kcpuset_copy, kcpuset_use, kcpuset_unuse, kcpuset_copyin, kcpuset_copyout, kcpuset_zero, kcpuset_fill, kcpuset_set, kcpuset_clear, kcpuset_isset, kcpuset_iszero, kcpuset_match, kcpuset_merge, kcpuset_atomic_set, kcpuset_atomic_clear — dynamic kernel CPU sets

# SYNOPSIS

#include <sys/kcpuset.h>

void
kcpuset_create(kcpuset_t **retkcp, bool zero);

void
kcpuset_destroy(kcpuset_t *kcp);

void
kcpuset_copy(kcpuset_t *dkcp, kcpuset_t *skcp);

void
kcpuset_use(kcpuset_t *kcp);

void
kcpuset_unuse(kcpuset_t *kcp, kcpuset_t **lst);

int
kcpuset_copyin(const cpuset_t *ucp, kcpuset_t *kcp, size_t len);

int
kcpuset_copyout(kcpuset_t *kcp, cpuset_t *ucp, size_t len);

void
kcpuset_zero(kcpuset_t *kcp);

void
kcpuset_fill(kcpuset_t *kcp);

void
kcpuset_set(kcpuset_t *kcp, cpuid_t cpu);

void
kcpuset_clear(kcpuset_t *kcp, cpuid_t cpu);

int
kcpuset_isset(kcpuset_t * kcp, cpuid_t cpu);

bool
kcpuset_iszero(kcpuset_t *kcp);

bool
kcpuset_match(const kcpuset_t *kcp1, const kcpuset_t *kcp2);

void
kcpuset_merge(kcpuset_t *kcp1, kcpuset_t *kcp2);

void
kcpuset_atomic_set(kcpuset_t *kcp, cpuid_t cpu);

void
kcpuset_atomic_clear(kcpuset_t *kcp, cpuid_t cpu);

# DESCRIPTION

The machine-independent kcpuset subsystem provides support for dynamic processor sets. Conceptually kcpuset can be understood to be the kernel equivalent of the user space cpuset(3) interface.

# FUNCTIONS

kcpuset_create(retkcp, zero)
  The kcpuset_create() function creates a dynamic CPU set and stores the result to retkcp. If the boolean zero is not false, the allocated set is also initialized to zero.
kcpuset_destroy(kcp)
  Destroys the CPU set kcp and schedules any linked CPU sets for deferred destruction.
kcpuset_copy(dkcp, skcp)
  Copies the CPU set pointed by skcp to dkcp.
kcpuset_use(kcp)
  Marks kcp as being in use by increasing the reference count of the object. Note that initially kcpuset_create() sets the reference count to 1.
kcpuset_unuse(kcp, lst)
  Decreases the internal reference count of kcp, and on the last reference (when the count reaches zero), destroys kcp. If lst is not NULL, then instead of destroying, kcp will be added to the lst list for a deferred destruction.
kcpuset_copyin(ucp, kcp, len)
  Copies the len bytes long user-space CPU set ucp to the kernel CPU set kcp.
kcpuset_copyout(kcp, ucp, len)
  Copies the kernel CPU set kcp to the user-space CPU set ucp.
kcpuset_zero(kcp)
  Clears the set kcp.
kcpuset_fill(kcp)
  Fills the whole set kcp with ones.
kcpuset_set(kcp, cpu)
  Adds cpu to the set kcp.
kcpuset_clear(kcp, cpu)
  Removes cpu from the set kcp.
kcpuset_isset(kcp, cpu)
  Returns 1 if cpu is part of the CPU set kcp.
kcpuset_iszero(kcp)
  Returns true if the set kcp is empty.
kcpuset_match(kcp1, kcp2)
  Compares the sets kcp1 and kcp2, returning true if these are identical.
kcpuset_merge(kcp1, kcp2)
  Merges the set kcp2 to the set kcp1.
kcpuset_atomic_set(kcp, cpu)
  The kcpuset_atomic_set() function operates as kcpuset_set(), but the operation is atomic; see atomic_ops(3) for more details.
kcpuset_atomic_clear(kcp, cpu)
  Removes cpu from the CPU set kcp atomically.

# CODE REFERENCES

The kcpuset subsystem is implemented within sys/kern/subr_kcpuset.c.

# SEE ALSO

cpuset(3)

# HISTORY

The kcpuset subsystem first appeared in NetBSD 6.0.

October 6, 2011 | NetBSD 5.99