Current File : //usr/share/src/uts/i86pc/sys/vm_machparam.h

/*	Copyright (c) 1988 AT&T	*/
/*	  All Rights Reserved  	*/
/*
 * Copyright (c) 1992, 2012, Oracle and/or its affiliates. All rights reserved.
 */

#ifndef _SYS_VM_MACHPARAM_H
#define	_SYS_VM_MACHPARAM_H


#ifdef	__cplusplus
extern "C" {
#endif

/*
 * Machine dependent constants for PC.
 */

/*
 * USRTEXT is the start of the user text/data space.
 */
#define	USRTEXT		USRSTACK

/*
 * Virtual memory related constants for UNIX resource control, all in bytes.
 * The default stack size (initial stack size limit) keeps the stack from
 * taking more than 2 page directory entries in addition to the part of
 * the page directory entry which also maps the initial text and data,
 * and makes the default slightly bigger than the 8MB on SPARC.
 */

/*
 * The stack grows down from just below KERNELBASE (see the definition of
 * USERLIMIT in i86pc/sys/machparam.h). Theoretically, it could grow down to
 * the top of the VA hole (0xffff800000000000), giving it a possible maximum of
 * about 1TB. For an xpv kernel, all user VA space is below the VA hole. The
 * theoretical maximum for the stack is about the same, although it can't grow
 * to quite that size, since it would clash with the heap.
 */
#define	MAXSSIZ		((1UL << 40) - (1UL << 30))	/* 1TB - 1GB */
#define	DFLSSIZ		(8*1024*1024 + ((USRSTACK) & 0x3FFFFF))

/*
 * The following are limits beyond which the hard or soft limits for stack
 * and data cannot be increased. These may be viewed as fundamental
 * characteristics of the system. Note: a bug in SVVS requires that the
 * default hard limit be increasable, so the default hard limit must be
 * less than these physical limits.
 */
#define	DSIZE_LIMIT	(USERLIMIT-USRTEXT)	/* physical data limit */
#define	SSIZE_LIMIT	(USRSTACK)		/* physical stack limit */

/*
 * Size of the kernel segkmem system pte table.  This virtual
 * space is controlled by the resource map "kernelmap".
 */
#define	SYSPTSIZE	((61*1024*1024) / MMU_PAGESIZE)

/*
 * Size of the ethernet addressable kernel segkmem system pte table.
 * This virtual space is controlled by the resource map "ekernelmap".
 * The ethernet interfaces in some sun machines can address only
 * the upper 16 Megabytes of memory.  Since the ethernet
 * driver kmem_allocs its memory, we bias all kmem_allocs
 * to try ekernelmap first and if it fails try kernelmap.
 * Folks that allocate directly out of kernelmap, above,
 * get memory that is non-ethernet addressable.
 */
#define	E_SYSPTSIZE	(0x2000000 / MMU_PAGESIZE)

/*
 * The time for a process to be blocked before being very swappable.
 * This is a number of seconds which the system takes as being a non-trivial
 * amount of real time. You probably shouldn't change this;
 * it is used in subtle ways (fractions and multiples of it are, that is, like
 * half of a ``long time'', almost a long time, etc.)
 * It is related to human patience and other factors which don't really
 * change over time.
 */
#define	MAXSLP 		20

/*
 * A swapped in process is given a small amount of core without being bothered
 * by the page replacement algorithm. Basically this says that if you are
 * swapped in you deserve some resources. We protect the last SAFERSS
 * pages against paging and will just swap you out rather than paging you.
 * Note that each process has at least UPAGES pages which are not
 * paged anyways so this number just means a swapped in process is
 * given around 32k bytes.
 */
/*
 * nominal ``small'' resident set size
 * protected against replacement
 */
#define	SAFERSS		3

/*
 * DISKRPM is used to estimate the number of paging i/o operations
 * which one can expect from a single disk controller.
 *
 * XXX - The system doesn't account for multiple swap devices.
 */
#define	DISKRPM		600

/*
 * The maximum value for handspreadpages which is the the distance
 * between the two clock hands in pages.
 */
#define	MAXHANDSPREADPAGES	((1ul * 1024 * 1024 * 1024) / PAGESIZE)

/*
 * Paged text files that are less than PGTHRESH bytes
 * may be "prefaulted in" instead of demand paged.
 */
#define	PGTHRESH	(512 * 1024)

#ifdef	__cplusplus
}
#endif

#endif	/* _SYS_VM_MACHPARAM_H */