cvs commit: src/sys/alpha/alpha pmap.c src/sys/pci agp.c agp_i810.c src/sys/vm vm_kern.c vm_page.c

[Alan Cox]

alc         2004/04/24 13:53:55 PDT

  FreeBSD src repository

  Modified files:
    sys/alpha/alpha      pmap.c 
    sys/pci              agp.c agp_i810.c 
    sys/vm               vm_kern.c vm_page.c 
  Log:
  Push down the responsibility for zeroing a physical page from the
  caller to vm_page_grab().  Although this gives VM_ALLOC_ZERO a
  different meaning for vm_page_grab() than for vm_page_alloc(), I feel
  such change is necessary to accomplish other goals.  Specifically, I
  want to make the PG_ZERO flag immutable between the time it is
  allocated by vm_page_alloc() and freed by vm_page_free() or
  vm_page_free_zero() to avoid locking overheads.  Once we gave up on
  the ability to automatically recognize a zeroed page upon entry to
  vm_page_free(), the ability to mutate the PG_ZERO flag became useless.
  Instead, I would like to say that "Once a page becomes valid, its
  PG_ZERO flag must be ignored."
  
  Revision  Changes    Path
  1.144     +0 -3      src/sys/alpha/alpha/pmap.c
  1.39      +0 -2      src/sys/pci/agp.c
  1.28      +0 -2      src/sys/pci/agp_i810.c
  1.116     +0 -2      src/sys/vm/vm_kern.c
  1.280     +2 -0      src/sys/vm/vm_page.c