allocate a page for a
() function allocates a page
. It is assumed that a page has not
already been allocated at pindex
. The page
returned is inserted into the object, unless
is specified in the
() will not sleep.
Its arguments are:
- The VM object to allocate the page for. The
object must be locked if
VM_ALLOC_NOOBJ is not specified.
- The index into the object at which the page should be inserted.
- 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:
The optional flags are:
- The page should be allocated with no special treatment.
- 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_page_alloc() is being called
during an interrupt. A page will be returned successfully if the free
page count is greater than zero.
- The returned page will not be exclusive busy.
- The returned page will not be included in any kernel core dumps
regardless of whether or not it is mapped in to KVA.
- Do not associate the allocated page with a vm object. The
object argument is ignored.
- The returned page will be shared busy.
- The returned page will be wired.
- 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
that was allocated is returned if
The pager process is always upgraded to
This manual page was written by Chad David