sys/uvm/uvm_pglist.h

   1 /*      $NetBSD: uvm_pglist.h,v 1.6 2008/04/28 20:24:12 martin Exp $    */
   2
   3 /*-
   4  * Copyright (c) 2000, 2001, 2008 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Jason R. Thorpe.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #ifndef _UVM_UVM_PGLIST_H_
  33 #define _UVM_UVM_PGLIST_H_
  34
  35 /*
  36  * This defines the type of a page queue, e.g. active list, inactive
  37  * list, etc.
  38  */
  39 TAILQ_HEAD(pglist, vm_page);
  40 LIST_HEAD(pgflist, vm_page);
  41
  42 /*
  43  * A page free list consists of free pages of unknown contents and free
  44  * pages of all zeros.
  45  */
  46 #define PGFL_UNKNOWN    0
  47 #define PGFL_ZEROS      1
  48 #define PGFL_NQUEUES    2
  49
  50 struct pgflbucket {
  51         struct pgflist pgfl_queues[PGFL_NQUEUES];
  52 };
  53
  54 struct pgfreelist {
  55         struct pgflbucket *pgfl_buckets;
  56 };
  57
  58 #endif /* _UVM_UVM_PGLIST_H_ */