freebsd-dev/sys/i386/include/param.h
Paul Saab c794ceb56a Implement write combining for crashdumps. This is useful when
write caching is disabled on both SCSI and IDE disks where large
memory dumps could take up to an hour to complete.

Taking an i386 scsi based system with 512MB of ram and timing (in
seconds) how long it took to complete a dump, the following results
were obtained:

Before:				After:
	WCE           TIME		WCE           TIME
	------------------		------------------
	1	141.820972		1	 15.600111
	0	797.265072		0	 65.480465

Obtained from:	Yahoo!
Reviewed by:	peter
2000-10-17 10:05:49 +00:00

158 lines
5.1 KiB
C

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)param.h 5.8 (Berkeley) 6/28/91
* $FreeBSD$
*/
#ifndef _MACHINE_PARAM_H_
#define _MACHINE_PARAM_H_
/*
* Machine dependent constants for Intel 386.
*/
#ifndef _MACHINE
#define _MACHINE i386
#endif
#ifndef MACHINE
#define MACHINE "i386"
#endif
#ifndef _MACHINE_ARCH
#define _MACHINE_ARCH i386
#endif
#ifndef MACHINE_ARCH
#define MACHINE_ARCH "i386"
#endif
#define MID_MACHINE MID_I386
/*
* OBJFORMAT_NAMES is a comma-separated list of the object formats
* that are supported on the architecture.
*/
#define OBJFORMAT_NAMES "elf", "aout"
#define OBJFORMAT_DEFAULT "elf"
#ifdef SMP
#define MAXCPU 16
#else
#define MAXCPU 1
#endif /* SMP */
/*
* Round p (pointer or byte index) up to a correctly-aligned value
* for all data types (int, long, ...). The result is unsigned int
* and must be cast to any desired pointer type.
*/
#define ALIGNBYTES (sizeof(int) - 1)
#define ALIGN(p) (((unsigned)(p) + ALIGNBYTES) & ~ALIGNBYTES)
#define PAGE_SHIFT 12 /* LOG2(PAGE_SIZE) */
#define PAGE_SIZE (1<<PAGE_SHIFT) /* bytes/page */
#define PAGE_MASK (PAGE_SIZE-1)
#define NPTEPG (PAGE_SIZE/(sizeof (pt_entry_t)))
#define NPDEPG (PAGE_SIZE/(sizeof (pd_entry_t)))
#define PDRSHIFT 22 /* LOG2(NBPDR) */
#define NBPDR (1<<PDRSHIFT) /* bytes/page dir */
#define PDRMASK (NBPDR-1)
#define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */
#define DEV_BSIZE (1<<DEV_BSHIFT)
#ifndef BLKDEV_IOSIZE
#define BLKDEV_IOSIZE PAGE_SIZE /* default block device I/O size */
#endif
#define DFLTPHYS (64 * 1024) /* default max raw I/O transfer size */
#define MAXPHYS (128 * 1024) /* max raw I/O transfer size */
#define MAXDUMPPGS (DFLTPHYS/PAGE_SIZE)
#define IOPAGES 2 /* pages of i/o permission bitmap */
#define UPAGES 2 /* pages of u-area */
/*
* Constants related to network buffer management.
* MCLBYTES must be no larger than PAGE_SIZE.
*/
#ifndef MSIZE
#define MSIZE 256 /* size of an mbuf */
#endif /* MSIZE */
#ifndef MCLSHIFT
#define MCLSHIFT 11 /* convert bytes to mbuf clusters */
#endif /* MCLSHIFT */
#define MCLBYTES (1 << MCLSHIFT) /* size of an mbuf cluster */
/*
* Some macros for units conversion
*/
/* clicks to bytes */
#define ctob(x) ((x)<<PAGE_SHIFT)
/* bytes to clicks */
#define btoc(x) (((unsigned)(x)+PAGE_MASK)>>PAGE_SHIFT)
/*
* btodb() is messy and perhaps slow because `bytes' may be an off_t. We
* want to shift an unsigned type to avoid sign extension and we don't
* want to widen `bytes' unnecessarily. Assume that the result fits in
* a daddr_t.
*/
#define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \
(sizeof (bytes) > sizeof(long) \
? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \
: (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT))
#define dbtob(db) /* calculates (db * DEV_BSIZE) */ \
((off_t)(db) << DEV_BSHIFT)
/*
* Mach derived conversion macros
*/
#define trunc_page(x) ((x) & ~PAGE_MASK)
#define round_page(x) (((x) + PAGE_MASK) & ~PAGE_MASK)
#define trunc_4mpage(x) ((unsigned)(x) & ~PDRMASK)
#define round_4mpage(x) ((((unsigned)(x)) + PDRMASK) & ~PDRMASK)
#define atop(x) ((unsigned)(x) >> PAGE_SHIFT)
#define ptoa(x) ((unsigned)(x) << PAGE_SHIFT)
#define i386_btop(x) ((unsigned)(x) >> PAGE_SHIFT)
#define i386_ptob(x) ((unsigned)(x) << PAGE_SHIFT)
#define pgtok(x) ((x) * (PAGE_SIZE / 1024))
#endif /* !_MACHINE_PARAM_H_ */