Differential D8530 Diff 22241 head/share/man/man9/vm_page_alloc.9

Changeset View

Standalone View

head/share/man/man9/vm_page_alloc.9

	Show All 20 Lines
	.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER			.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT			.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY			.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH			.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
	.\" DAMAGE.			.\" DAMAGE.
	.\"			.\"
	.\" $FreeBSD$			.\" $FreeBSD$
	.\"			.\"
	.Dd January 28, 2012			.Dd November 16, 2016
	.Dt VM_PAGE_ALLOC 9			.Dt VM_PAGE_ALLOC 9
	.Os			.Os
	.Sh NAME			.Sh NAME
	.Nm vm_page_alloc			.Nm vm_page_alloc
	.Nd "allocate a page for a"			.Nd "allocate a page for a"
	.Vt vm_object			.Vt vm_object
	.Sh SYNOPSIS			.Sh SYNOPSIS
	.In sys/param.h			.In sys/param.h
	Show All 9 Lines
	within			within
	.Fa object .			.Fa object .
	It is assumed that a page has not already been allocated at			It is assumed that a page has not already been allocated at
	.Fa pindex .			.Fa pindex .
	The page returned is inserted into the object, unless			The page returned is inserted into the object, unless
	.Dv VM_ALLOC_NOOBJ			.Dv VM_ALLOC_NOOBJ
	is specified in the			is specified in the
	.Fa req .			.Fa req .
	The page may exist in the vm object cache, in which case it will
	be reactivated instead, moving from the cache into the object page list.
	.Pp			.Pp
	.Fn vm_page_alloc			.Fn vm_page_alloc
	will not sleep.			will not sleep.
	.Pp			.Pp
	Its arguments are:			Its arguments are:
	.Bl -tag -width ".Fa object"			.Bl -tag -width ".Fa object"
	.It Fa object			.It Fa object
	The VM object to allocate the page for.			The VM object to allocate the page for.
	Show All 19 Lines
	.It Dv VM_ALLOC_INTERRUPT			.It Dv VM_ALLOC_INTERRUPT
	.Fn vm_page_alloc			.Fn vm_page_alloc
	is being called during an interrupt.			is being called during an interrupt.
	A page will be returned successfully if the free page count is greater			A page will be returned successfully if the free page count is greater
	than zero.			than zero.
	.El			.El
	.Pp			.Pp
	The optional flags are:			The optional flags are:
	.Bl -tag -width ".Dv VM_ALLOC_IFNOTCACHED"			.Bl -tag -width ".Dv VM_ALLOC_NOBUSY"
	.It Dv VM_ALLOC_NOBUSY			.It Dv VM_ALLOC_NOBUSY
	The returned page will not be exclusive busy.			The returned page will not be exclusive busy.
	.It Dv VM_ALLOC_NODUMP			.It Dv VM_ALLOC_NODUMP
	The returned page will not be included in any kernel core dumps			The returned page will not be included in any kernel core dumps
	regardless of whether or not it is mapped in to KVA.			regardless of whether or not it is mapped in to KVA.
	.It Dv VM_ALLOC_NOOBJ			.It Dv VM_ALLOC_NOOBJ
	Do not associate the allocated page with a vm object.			Do not associate the allocated page with a vm object.
	The			The
	.Fa object			.Fa object
	argument is ignored.			argument is ignored.
	.It Dv VM_ALLOC_IFCACHED
	Allocate the page only if it is cached.
	Otherwise, return
	.Dv NULL .
	.It Dv VM_ALLOC_IFNOTCACHED
	Only allocate the page if it is not cached in the
	.Fa object .
	If the page at the specified
	.Fa pindex
	is cached, NULL is returned instead.
	.It Dv VM_ALLOC_SBUSY			.It Dv VM_ALLOC_SBUSY
	The returned page will be shared busy.			The returned page will be shared busy.
	.It Dv VM_ALLOC_WIRED			.It Dv VM_ALLOC_WIRED
	The returned page will be wired.			The returned page will be wired.
	.It Dv VM_ALLOC_ZERO			.It Dv VM_ALLOC_ZERO
	Indicate a preference for a pre-zeroed page.			Indicate a preference for a pre-zeroed page.
	There is no guarantee that the returned page will be zeroed, but it			There is no guarantee that the returned page will be zeroed, but it
	will have the			will have the
	Show All 19 Lines