NetBSD/sys/uvm/uvm_param.h
atatat df0a9badc6 Introduce "top down" memory management for mmap()ed allocations. This
means that the dynamic linker gets mapped in at the top of available
user virtual memory (typically just below the stack), shared libraries
get mapped downwards from that point, and calls to mmap() that don't
specify a preferred address will get mapped in below those.

This means that the heap and the mmap()ed allocations will grow
towards each other, allowing one or the other to grow larger than
before.  Previously, the heap was limited to MAXDSIZ by the placement
of the dynamic linker (and the process's rlimits) and the space
available to mmap was hobbled by this reservation.

This is currently only enabled via an *option* for the i386 platform
(though other platforms are expected to follow).  Add "options
USE_TOPDOWN_VM" to your kernel config file, rerun config, and rebuild
your kernel to take advantage of this.

Note that the pmap_prefer() interface has not yet been modified to
play nicely with this, so those platforms require a bit more work
(most notably the sparc) before they can use this new memory
arrangement.

This change also introduces a VM_DEFAULT_ADDRESS() macro that picks
the appropriate default address based on the size of the allocation or
the size of the process's text segment accordingly.  Several drivers
and the SYSV SHM address assignment were changed to use this instead
of each one picking their own "default".
2003-02-20 22:16:05 +00:00

214 lines
7.4 KiB
C

/* $NetBSD: uvm_param.h,v 1.14 2003/02/20 22:16:08 atatat Exp $ */
/*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* 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.
*
* @(#)vm_param.h 8.2 (Berkeley) 1/9/95
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* Machine independent virtual memory parameters.
*/
#ifndef _VM_PARAM_
#define _VM_PARAM_
#ifdef _KERNEL_OPT
#include "opt_uvm.h"
#endif
#ifdef _KERNEL
#include <machine/vmparam.h>
#endif
/*
* This belongs in types.h, but breaks too many existing programs.
*/
typedef int boolean_t;
#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif
/*
* The machine independent pages are refered to as PAGES. A page
* is some number of hardware pages, depending on the target machine.
*/
#define DEFAULT_PAGE_SIZE 4096
#if defined(_KERNEL) && !defined(PAGE_SIZE)
/*
* All references to the size of a page should be done with PAGE_SIZE
* or PAGE_SHIFT. The fact they are variables is hidden here so that
* we can easily make them constant if we so desire.
*/
#define PAGE_SIZE uvmexp.pagesize /* size of page */
#define PAGE_MASK uvmexp.pagemask /* size of page - 1 */
#define PAGE_SHIFT uvmexp.pageshift /* bits to shift for pages */
#endif /* _KERNEL */
/*
* CTL_VM identifiers
*/
#define VM_METER 1 /* struct vmmeter */
#define VM_LOADAVG 2 /* struct loadavg */
#define VM_UVMEXP 3 /* struct uvmexp */
#define VM_NKMEMPAGES 4 /* kmem_map pages */
#define VM_UVMEXP2 5 /* struct uvmexp_sysctl */
#define VM_ANONMIN 6
#define VM_EXECMIN 7
#define VM_FILEMIN 8
#define VM_MAXSLP 9
#define VM_USPACE 10
#define VM_ANONMAX 11
#define VM_EXECMAX 12
#define VM_FILEMAX 13
#define VM_MAXID 14 /* number of valid vm ids */
#define CTL_VM_NAMES { \
{ 0, 0 }, \
{ "vmmeter", CTLTYPE_STRUCT }, \
{ "loadavg", CTLTYPE_STRUCT }, \
{ "uvmexp", CTLTYPE_STRUCT }, \
{ "nkmempages", CTLTYPE_INT }, \
{ "uvmexp2", CTLTYPE_STRUCT }, \
{ "anonmin", CTLTYPE_INT }, \
{ "execmin", CTLTYPE_INT }, \
{ "filemin", CTLTYPE_INT }, \
{ "maxslp", CTLTYPE_INT }, \
{ "uspace", CTLTYPE_INT }, \
{ "anonmax", CTLTYPE_INT }, \
{ "execmax", CTLTYPE_INT }, \
{ "filemax", CTLTYPE_INT }, \
}
#ifndef ASSEMBLER
/*
* Convert addresses to pages and vice versa.
* No rounding is used.
*/
#ifdef _KERNEL
#define atop(x) (((paddr_t)(x)) >> PAGE_SHIFT)
#define ptoa(x) ((vaddr_t)((vaddr_t)(x) << PAGE_SHIFT))
/*
* Round off or truncate to the nearest page. These will work
* for either addresses or counts (i.e., 1 byte rounds to 1 page).
*/
#define round_page(x) (((x) + PAGE_MASK) & ~PAGE_MASK)
#define trunc_page(x) ((x) & ~PAGE_MASK)
/*
* Set up the default mapping address (VM_DEFAULT_ADDRESS) according to:
*
* USE_TOPDOWN_VM: a kernel option to enable on a per-kernel basis
* which only be used on ports that define...
* __HAVE_TOPDOWN_VM: a per-port option to offer the topdown option
*
* __USE_TOPDOWN_VM: a per-port option to unconditionally use it
*
* if __USE_TOPDOWN_VM is defined, the port can specify a default vm
* address, or we will use the topdown default from below. If it is
* NOT defined, then the port can offer topdown as an option, but it
* MUST define the VM_DEFAULT_ADDRESS macro itself.
*/
#if defined(USE_TOPDOWN_VM) || defined(__USE_TOPDOWN_VM)
# if !defined(__HAVE_TOPDOWN_VM) && !defined(__USE_TOPDOWN_VM)
# error "Top down memory allocation not enabled for this system"
# else /* !__HAVE_TOPDOWN_VM && !__USE_TOPDOWN_VM */
# define __USING_TOPDOWN_VM
# if !defined(VM_DEFAULT_ADDRESS)
# if !defined(__USE_TOPDOWN_VM)
# error "Top down memory allocation not configured for this system"
# else /* !__USE_TOPDOWN_VM */
# define VM_DEFAULT_ADDRESS(da, sz) \
trunc_page(VM_MAXUSER_ADDRESS - MAXSSIZ - (sz))
# endif /* !__USE_TOPDOWN_VM */
# endif /* !VM_DEFAULT_ADDRESS */
# endif /* !__HAVE_TOPDOWN_VM && !__USE_TOPDOWN_VM */
#endif /* USE_TOPDOWN_VM || __USE_TOPDOWN_VM */
#if !defined(__USING_TOPDOWN_VM)
# if defined(VM_DEFAULT_ADDRESS)
# error "Default vm address should not be defined here"
# else /* VM_DEFAULT_ADDRESS */
# define VM_DEFAULT_ADDRESS(da, sz) round_page((vaddr_t)(da) + MAXDSIZ)
# endif /* VM_DEFAULT_ADDRESS */
#endif /* !__USING_TOPDOWN_VM */
extern psize_t mem_size; /* size of physical memory (bytes) */
extern int ubc_nwins; /* number of UBC mapping windows */
extern int ubc_winshift; /* shift for a UBC mapping window */
#else
/* out-of-kernel versions of round_page and trunc_page */
#define round_page(x) \
((((vaddr_t)(x) + (vm_page_size - 1)) / vm_page_size) * \
vm_page_size)
#define trunc_page(x) \
((((vaddr_t)(x)) / vm_page_size) * vm_page_size)
#endif /* _KERNEL */
#endif /* ASSEMBLER */
#endif /* _VM_PARAM_ */