0d94caffca
much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
225 lines
8.1 KiB
C
225 lines
8.1 KiB
C
/*-
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* Copyright (c) 1982, 1986, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)param.h 8.2 (Berkeley) 1/21/94
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* $Id: param.h,v 1.5 1994/09/01 05:12:51 davidg Exp $
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*/
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#ifndef _SYS_PARAM_H_
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#define _SYS_PARAM_H_
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#define BSD 199306 /* System version (year & month). */
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#define BSD4_3 1
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#define BSD4_4 1
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#ifndef NULL
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#define NULL 0
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#endif
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#ifndef LOCORE
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#include <sys/types.h>
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#endif
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/*
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* Machine-independent constants (some used in following include files).
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* Redefined constants are from POSIX 1003.1 limits file.
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*
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* MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
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* MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
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*/
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#include <sys/syslimits.h>
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#define MAXCOMLEN 16 /* max command name remembered */
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#define MAXINTERP 32 /* max interpreter file name length */
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#define MAXLOGNAME 12 /* max login name length */
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#define MAXUPRC CHILD_MAX /* max simultaneous processes */
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#define NCARGS ARG_MAX /* max bytes for an exec function */
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#define NGROUPS NGROUPS_MAX /* max number groups */
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#define NOFILE OPEN_MAX /* max open files per process */
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#define NOGROUP 65535 /* marker for empty group set member */
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#define MAXHOSTNAMELEN 256 /* max hostname size */
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/* More types and definitions used throughout the kernel. */
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#ifdef KERNEL
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#include <sys/cdefs.h>
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#include <sys/errno.h>
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#include <sys/time.h>
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#include <sys/resource.h>
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#include <sys/ucred.h>
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#include <sys/uio.h>
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#include <sys/rtprio.h>
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#endif
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/* Signals. */
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#include <sys/signal.h>
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/* Machine type dependent parameters. */
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#include <machine/param.h>
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#include <machine/limits.h>
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/*
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* Priorities. Note that with 32 run queues, differences less than 4 are
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* insignificant.
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*/
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#define PSWP 0
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#define PVM 4
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#define PINOD 8
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#define PRIBIO 16
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#define PVFS 20
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#define PZERO 22 /* No longer magic, shouldn't be here. XXX */
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#define PSOCK 24
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#define PWAIT 32
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#define PLOCK 36
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#define PPAUSE 40
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#define PUSER 50
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#define MAXPRI 127 /* Priorities range from 0 through MAXPRI. */
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#define PRIMASK 0x0ff
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#define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */
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#define NZERO 0 /* default "nice" */
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#define NBPW sizeof(int) /* number of bytes per word (integer) */
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#define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
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#define NODEV (dev_t)(-1) /* non-existent device */
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/*
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* Clustering of hardware pages on machines with ridiculously small
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* page sizes is done here. The paging subsystem deals with units of
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* CLSIZE pte's describing NBPG (from machine/machparam.h) pages each.
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*/
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#define CLBYTES (CLSIZE*NBPG)
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#define CLOFSET (CLSIZE*NBPG-1) /* for clusters, like PGOFSET */
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#define claligned(x) ((((int)(x))&CLOFSET)==0)
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#define CLOFF CLOFSET
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#define CLSHIFT (PGSHIFT+CLSIZELOG2)
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#if CLSIZE==1
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#define clbase(i) (i)
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#define clrnd(i) (i)
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#else
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/* Give the base virtual address (first of CLSIZE). */
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#define clbase(i) ((i) &~ (CLSIZE-1))
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/* Round a number of clicks up to a whole cluster. */
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#define clrnd(i) (((i) + (CLSIZE-1)) &~ (CLSIZE-1))
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#endif
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#define CBLOCK 128 /* Clist block size, must be a power of 2. */
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#define CBQSIZE (CBLOCK/NBBY) /* Quote bytes/cblock - can do better. */
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/* Data chars/clist. */
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#define CBSIZE (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
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#define CROUND (CBLOCK - 1) /* Clist rounding. */
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/*
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* File system parameters and macros.
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*
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* The file system is made out of blocks of at most MAXBSIZE units, with
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* smaller units (fragments) only in the last direct block. MAXBSIZE
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* primarily determines the size of buffers in the buffer pool. It may be
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* made larger without any effect on existing file systems; however making
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* it smaller make make some file systems unmountable. Also, MAXBSIZE
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* must be less than MAXPHYS!!!
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*/
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#define MAXBSIZE 16384
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#define MAXFRAG 8
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/*
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* MAXPATHLEN defines the longest permissable path length after expanding
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* symbolic links. It is used to allocate a temporary buffer from the buffer
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* pool in which to do the name expansion, hence should be a power of two,
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* and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
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* maximum number of symbolic links that may be expanded in a path name.
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* It should be set high enough to allow all legitimate uses, but halt
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* infinite loops reasonably quickly.
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*/
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#define MAXPATHLEN PATH_MAX
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#define MAXSYMLINKS 8
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/* Bit map related macros. */
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#define setbit(a,i) ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
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#define clrbit(a,i) ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
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#define isset(a,i) ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
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#define isclr(a,i) (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
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/* Macros for counting and rounding. */
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#ifndef howmany
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#define howmany(x, y) (((x)+((y)-1))/(y))
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#endif
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#define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
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#define powerof2(x) ((((x)-1)&(x))==0)
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/* Macros for min/max. */
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#ifndef KERNEL
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#define MIN(a,b) (((a)<(b))?(a):(b))
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#define MAX(a,b) (((a)>(b))?(a):(b))
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#endif
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/*
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* Constants for setting the parameters of the kernel memory allocator.
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*
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* 2 ** MINBUCKET is the smallest unit of memory that will be
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* allocated. It must be at least large enough to hold a pointer.
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*
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* Units of memory less or equal to MAXALLOCSAVE will permanently
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* allocate physical memory; requests for these size pieces of
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* memory are quite fast. Allocations greater than MAXALLOCSAVE must
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* always allocate and free physical memory; requests for these
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* size allocations should be done infrequently as they will be slow.
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*
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* Constraints: CLBYTES <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
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* MAXALLOCSIZE must be a power of two.
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*/
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#define MINBUCKET 4 /* 4 => min allocation of 16 bytes */
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#define MAXALLOCSAVE (2 * CLBYTES)
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/*
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* Scale factor for scaled integers used to count %cpu time and load avgs.
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*
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* The number of CPU `tick's that map to a unique `%age' can be expressed
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* by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
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* can be calculated (assuming 32 bits) can be closely approximated using
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* the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
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*
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* For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
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* FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
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*/
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#define FSHIFT 11 /* bits to right of fixed binary point */
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#define FSCALE (1<<FSHIFT)
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#endif
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