freebsd man page for vm_page_grab

VM_PAGE_GRAB(9) 					   BSD Kernel Developer's Manual					   VM_PAGE_GRAB(9)

NAME
     vm_page_grab -- returns a page from an object

SYNOPSIS
     #include <sys/param.h>
     #include <vm/vm.h>
     #include <vm/vm_page.h>

     vm_page_t
     vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags);

DESCRIPTION
     The vm_page_grab() function returns the page at pindex from the given object.  If the page exists and is busy, vm_page_grab() will sleep
     while waiting for it.  If the page does not exist, it is allocated.  The function sleeps until the allocation request can be satisfied.

     The function requires the object to be locked on entry, and returns with the object locked.  If the vm_page_grab() function sleeps for any
     reason, the object lock is temporary dropped.

     The vm_page_grab() supports all of the flags supported by vm_page_alloc(9).  In addition, vm_page_grab() supports the following flags:

     VM_ALLOC_IGN_SBUSY  When waiting for the busy state of the existing page to drain, only test for exclusive busy; ignore the shared busy
			 counter.

RETURN VALUES
     The vm_page_grab() always returns the page.

SEE ALSO
     vm_page_alloc(9)

AUTHORS
     This manual page was written by Chad David <davidc@acns.ab.ca>.

BSD
								  August 23, 2013							       BSD