vm_page_insert(9) [freebsd man page]

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

NAME

     vm_page_insert, vm_page_remove -- add/remove page from an object

SYNOPSIS

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

     void
     vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex);

     void
     vm_page_remove(vm_page_t m);

DESCRIPTION

     The vm_page_insert() function adds a page to the given object at the given index.	The page is added to both the VM page hash table and to
     the object's list of pages, but the hardware page tables are not updated.	In the case of a user page, it will be faulted in when it is
     accessed.	If the page is a kernel page, the caller is expected to handle adding the page to the kernel's pmap.

     If PG_WRITEABLE is set in the page's flags, OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY are set in the object's flags.

     The vm_page_remove() function removes the given page from its object, and from the VM page hash table.  The page must be busy prior to this
     call, or the system will panic.  The pmap entry for the page is not removed by this function.

     The arguments to vm_page_insert() are:

     m	     The page to add to the object.

     object  The object the page should be added to.

     pindex  The index into the object the page should be at.

     The arguments to vm_page_remove() are:

     m	The page to remove.

IMPLEMENTATION NOTES

     The index of a page in a VM object is the byte index into the same object truncated to a page boundary.  For example, if the page size is
     4096 bytes, and the address in the object is 81944, the page index is 20.

AUTHORS

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

BSD
								   July 17, 2001							       BSD

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

NAME

     vm_page_alloc -- allocate a page for a vm_object

SYNOPSIS

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

     vm_page_t
     vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req);

DESCRIPTION

     The vm_page_alloc() function allocates a page at pindex within object.  It is assumed that a page has not already been allocated at pindex.
     The page returned is inserted into the object, unless VM_ALLOC_NOOBJ is specified in the 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.

     vm_page_alloc() will not sleep.

     Its arguments are:

     object  The VM object to allocate the page for.  The object must be locked if VM_ALLOC_NOOBJ is not specified.

     pindex  The index into the object at which the page should be inserted.

     req     The bitwise-inclusive OR of a class and any optional flags indicating how the page should be allocated.

	     Exactly one of the following classes must be specified:

	     VM_ALLOC_NORMAL	 The page should be allocated with no special treatment.

	     VM_ALLOC_SYSTEM	 The page can be allocated if the cache is empty and the free page count is above the interrupt reserved water
				 mark.	This flag should be used only when the system really needs the page.

	     VM_ALLOC_INTERRUPT  vm_page_alloc() is being called during an interrupt.  A page will be returned successfully if the free page count
				 is greater than zero.

	     The optional flags are:

	     VM_ALLOC_NOBUSY	   The returned page will not be exclusive busy.

	     VM_ALLOC_NODUMP	   The returned page will not be included in any kernel core dumps regardless of whether or not it is mapped in to
				   KVA.

	     VM_ALLOC_NOOBJ	   Do not associate the allocated page with a vm object.  The object argument is ignored.

	     VM_ALLOC_IFCACHED	   Allocate the page only if it is cached.  Otherwise, return NULL.

	     VM_ALLOC_IFNOTCACHED  Only allocate the page if it is not cached in the object.  If the page at the specified pindex is cached, NULL
				   is returned instead.

	     VM_ALLOC_SBUSY	   The returned page will be shared busy.

	     VM_ALLOC_WIRED	   The returned page will be wired.

	     VM_ALLOC_ZERO	   Indicate a preference for a pre-zeroed page.  There is no guarantee that the returned page will be zeroed, but
				   it will have the PG_ZERO flag set if it is zeroed.

RETURN VALUES

     The vm_page_t that was allocated is returned if successful; otherwise, NULL is returned.

NOTES

     The pager process is always upgraded to VM_ALLOC_SYSTEM unless VM_ALLOC_INTERRUPT is set.

AUTHORS

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

BSD
								 January 28, 2012							       BSD