table of contents
| VM_PAGE_BITS(9) | Kernel Developer's Manual | VM_PAGE_BITS(9) | 
NAME¶
vm_page_bits,
  vm_page_set_validclean,
  vm_page_clear_dirty,
  vm_page_set_invalid,
  vm_page_zero_invalid,
  vm_page_is_valid,
  vm_page_test_dirty,
  vm_page_dirty, vm_page_undirty
  —
SYNOPSIS¶
#include <sys/param.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
int
  
  vm_page_bits(int
    base, int
  size);
void
  
  vm_page_set_validclean(vm_page_t
    m, int base,
    int size);
void
  
  vm_page_clear_dirty(vm_page_t
    m, int base,
    int size);
void
  
  vm_page_set_invalid(vm_page_t
    m, int base,
    int size);
void
  
  vm_page_zero_invalid(vm_page_t
    m, boolean_t
    setvalid);
int
  
  vm_page_is_valid(vm_page_t
    m, int base,
    int size);
void
  
  vm_page_test_dirty(vm_page_t
    m);
void
  
  vm_page_dirty(vm_page_t
    m);
void
  
  vm_page_undirty(vm_page_t
    m);
DESCRIPTION¶
vm_page_bits() calculates the bits representing the
  DEV_BSIZE range of bytes between
  base and size. The byte range is
  expected to be within a single page, and if size is
  zero, no bits will be set.
vm_page_set_validclean() flags the byte
    range between base and size as
    valid and clean. The range is expected to be
    DEV_BSIZE aligned and no larger than
    PAGE_SIZE. If it is not properly aligned, any
    unaligned chunks of the DEV_BSIZE blocks at the
    beginning and end of the range will be zeroed.
If base is zero and
    size is one page, the modified bit in the page map is
    cleared; as well, the VPO_NOSYNC flag is
  cleared.
vm_page_clear_dirty() clears the dirty
    bits within a page in the range between base and
    size. The bits representing the range are calculated
    by calling vm_page_bits().
vm_page_set_invalid() clears the bits in
    both the valid and dirty flags representing the
    DEV_BSIZE blocks between base
    and size in the page. The bits are calculated by
    calling vm_page_bits(). As well as clearing the bits
    within the page, the generation number within the object holding the page is
    incremented.
vm_page_zero_invalid() zeroes all of the
    blocks within the page that are currently flagged as invalid. If
    setvalid is TRUE, all of the
    valid bits within the page are set.
In some cases, such as NFS, the valid bits cannot be set in order to maintain cache consistency.
vm_page_is_valid() checks to determine if
    the all of the DEV_BSIZE blocks between
    base and size of the page are
    valid. If size is zero and the page is entirely
    invalid vm_page_is_valid() will return
    TRUE, in all other cases a size of zero will return
    FALSE.
vm_page_test_dirty() checks if a page has
    been modified via any of its physical maps, and if so, flags the entire page
    as dirty. vm_page_dirty() is called to modify the
    dirty bits.
vm_page_dirty() flags the entire page as
    dirty. It is expected that the page is not currently on the cache queue.
vm_page_undirty() clears all of the dirty
    bits in a page.
NOTES¶
None of these functions are allowed to block.AUTHORS¶
This manual page was written by Chad David <davidc@acns.ab.ca>.| December 1, 2001 | Linux 4.9.0-9-amd64 |