NAME

       UFFDIO_WAKE - wake up a thread waiting for page-fault resolution

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <linux/userfaultfd.h>  /* Definition of UFFD* constants */
       #include <sys/ioctl.h>

       int ioctl(int fd, UFFDIO_WAKE, const struct uffdio_range *argp);

DESCRIPTION

       Wake up the thread waiting for page-fault resolution on a specified memory address range.

       The  UFFDIO_WAKE  operation  is  used  in conjunction with UFFDIO_COPY and UFFDIO_ZEROPAGE
       operations that have the UFFDIO_COPY_MODE_DONTWAKE  or  UFFDIO_ZEROPAGE_MODE_DONTWAKE  bit
       set  in  the  mode  field.   The  userfault  monitor  can  perform several UFFDIO_COPY and
       UFFDIO_ZEROPAGE operations in a batch and then explicitly  wake  up  the  faulting  thread
       using UFFDIO_WAKE.

RETURN VALUE

       This  ioctl(2)  operation returns 0 on success.  On error, -1 is returned and errno is set
       to indicate the error.

ERRORS

       EINVAL The start or the len field of the ufdio_range structure was not a multiple  of  the
              system page size; or len was zero; or the specified range was otherwise invalid.

STANDARDS

       Linux.

HISTORY

       Linux 4.3.

EXAMPLES

       See userfaultfd(2).

SEE ALSO

       ioctl(2), ioctl_userfaultfd(2), UFFDIO_REGISTER(2const), userfaultfd(2)

       linux.git/Documentation/admin-guide/mm/userfaultfd.rst