UFFDIO_CONTINUE(2const) UFFDIO_CONTINUE(2const)
NAME
UFFDIO_CONTINUE - resolve a minor page fault
LIBRARY
Standard C library (libc, -lc)
SYNOPSIS
#include <linux/userfaultfd.h> /* Definition of UFFD* constants */
#include <sys/ioctl.h>
int ioctl(int fd, UFFDIO_CONTINUE, struct uffdio_continue *argp);
#include <linux/userfaultfd.h>
struct uffdio_continue {
struct uffdio_range range;
/* Range to install PTEs for and continue */
__u64 mode; /* Flags controlling the behavior of continue */
__s64 mapped; /* Number of bytes mapped, or negated error */
};
DESCRIPTION
Resolve a minor page fault by installing page table entries for existing
pages in the page cache.
The following value may be bitwise ORed in mode to change the behavior
of the UFFDIO_CONTINUE operation:
UFFDIO_CONTINUE_MODE_DONTWAKE
Do not wake up the thread that waits for page-fault resolution.
The mapped field is used by the kernel to return the number of bytes
that were actually mapped, or an error in the same manner as UFF-
DIO_COPY. If the value returned in the mapped field doesn't match the
value that was specified in range.len, the operation fails with the er-
ror EAGAIN. The mapped field is output-only; it is not read by the UFF-
DIO_CONTINUE operation.
RETURN VALUE
This ioctl(2) operation returns 0 on success. In this case, the entire
area was mapped. On error, -1 is returned and errno is set to indicate
the error.
ERRORS
EAGAIN The number of bytes mapped (i.e., the value returned in the
mapped field) does not equal the value that was specified in the
range.len field.
EEXIST One or more pages were already mapped in the given range.
EFAULT No existing page could be found in the page cache for the given
range.
EINVAL Either range.start or range.len was not a multiple of the system
page size; or range.len was zero; or the range specified was in-
valid.
EINVAL An invalid bit was specified in the mode field.
ENOENT The faulting process has changed its virtual memory layout simul-
taneously with an outstanding UFFDIO_CONTINUE operation.
ENOMEM Allocating memory needed to setup the page table mappings failed.
ESRCH The faulting process has exited at the time of a UFFDIO_CONTINUE
operation.
STANDARDS
Linux.
HISTORY
Linux 5.13.
EXAMPLES
See userfaultfd(2).
SEE ALSO
ioctl(2), ioctl_userfaultfd(2), userfaultfd(2)
linux.git/Documentation/admin-guide/mm/userfaultfd.rst
Linux man-pages 6.9.1 2024-06-17 UFFDIO_CONTINUE(2const)
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