determine residency of memory pages
Standard C Library (libc, -lc)
() system call determines whether
each of the pages in the region beginning at
and continuing for
bytes is resident. The status is returned
in the vec
array, one character per page.
Each character is either 0 if the page is not resident, or a combination of
the following flags (defined in
- Page is in core (resident).
- Page has been referenced by us.
- Page has been modified by us.
- Page has been referenced.
- Page has been modified.
- Page is part of a large (“super”) page.
The information returned by
() may be
out of date by the time the system call returns. The only way to ensure that a
page is resident is to lock it into memory with the
() function returns the
value 0 if successful; otherwise the value -1 is returned and
the global variable errno
is set to indicate
() system call will fail if:
- The virtual address range specified by the
len arguments is not fully mapped.
- The vec argument points to an illegal
() system call first appeared in