freebsd-dev/sys/vm/vm_extern.h
Peter Wemm a2a1c95c10 The biggie: Get rid of the UPAGES from the top of the per-process address
space. (!)

Have each process use the kernel stack and pcb in the kvm space.  Since
the stacks are at a different address, we cannot copy the stack at fork()
and allow the child to return up through the function call tree to return
to user mode - create a new execution context and have the new process
begin executing from cpu_switch() and go to user mode directly.
In theory this should speed up fork a bit.

Context switch the tss_esp0 pointer in the common tss.  This is a lot
simpler since than swithching the gdt[GPROC0_SEL].sd.sd_base pointer
to each process's tss since the esp0 pointer is a 32 bit pointer, and the
sd_base setting is split into three different bit sections at non-aligned
boundaries and requires a lot of twiddling to reset.

The 8K of memory at the top of the process space is now empty, and unmapped
(and unmappable, it's higher than VM_MAXUSER_ADDRESS).

Simplity the pmap code to manage process contexts, we no longer have to
double map the UPAGES, this simplifies and should measuably speed up fork().

The following parts came from John Dyson:

Set PG_G on the UPAGES that are now in kernel context, and invalidate
them when swapping them out.

Move the upages object (upobj) from the vmspace to the proc structure.

Now that the UPAGES (pcb and kernel stack) are out of user space, make
rfork(..RFMEM..) do what was intended by sharing the vmspace
entirely via reference counting rather than simply inheriting the mappings.
1997-04-07 07:16:06 +00:00

104 lines
4.6 KiB
C

/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* 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_extern.h 8.2 (Berkeley) 1/12/94
* $Id: vm_extern.h,v 1.32 1997/04/06 02:30:56 dyson Exp $
*/
#ifndef _VM_EXTERN_H_
#define _VM_EXTERN_H_
struct buf;
struct proc;
struct vmspace;
struct vmtotal;
struct mount;
struct vnode;
#ifdef KERNEL
#ifdef TYPEDEF_FOR_UAP
int getpagesize __P((struct proc * p, void *, int *));
int madvise __P((struct proc *, void *, int *));
int mincore __P((struct proc *, void *, int *));
int mprotect __P((struct proc *, void *, int *));
int msync __P((struct proc *, void *, int *));
int munmap __P((struct proc *, void *, int *));
int obreak __P((struct proc *, void *, int *));
int sbrk __P((struct proc *, void *, int *));
int smmap __P((struct proc *, void *, int *));
int sstk __P((struct proc *, void *, int *));
int swapon __P((struct proc *, void *, int *));
#endif
void faultin __P((struct proc *p));
int grow __P((struct proc *, u_int));
int kernacc __P((caddr_t, int, int));
vm_offset_t kmem_alloc __P((vm_map_t, vm_size_t));
vm_offset_t kmem_alloc_pageable __P((vm_map_t, vm_size_t));
vm_offset_t kmem_alloc_wait __P((vm_map_t, vm_size_t));
void kmem_free __P((vm_map_t, vm_offset_t, vm_size_t));
void kmem_free_wakeup __P((vm_map_t, vm_offset_t, vm_size_t));
void kmem_init __P((vm_offset_t, vm_offset_t));
vm_offset_t kmem_malloc __P((vm_map_t, vm_size_t, boolean_t));
vm_map_t kmem_suballoc __P((vm_map_t, vm_offset_t *, vm_offset_t *, vm_size_t, boolean_t));
void munmapfd __P((struct proc *, int));
int pager_cache __P((vm_object_t, boolean_t));
int swaponvp __P((struct proc *, struct vnode *, dev_t , u_long));
void swapout_procs __P((void));
int useracc __P((caddr_t, int, int));
int vm_fault __P((vm_map_t, vm_offset_t, vm_prot_t, int));
void vm_fault_copy_entry __P((vm_map_t, vm_map_t, vm_map_entry_t, vm_map_entry_t));
void vm_fault_unwire __P((vm_map_t, vm_offset_t, vm_offset_t));
int vm_fault_wire __P((vm_map_t, vm_offset_t, vm_offset_t));
int vm_fault_user_wire __P((vm_map_t, vm_offset_t, vm_offset_t));
void vm_fork __P((struct proc *, struct proc *, int));
int vm_mmap __P((vm_map_t, vm_offset_t *, vm_size_t, vm_prot_t, vm_prot_t, int, caddr_t, vm_ooffset_t));
vm_offset_t vm_page_alloc_contig __P((vm_offset_t, vm_offset_t, vm_offset_t, vm_offset_t));
void vm_set_page_size __P((void));
void vmmeter __P((void));
struct vmspace *vmspace_alloc __P((vm_offset_t, vm_offset_t, int));
struct vmspace *vmspace_fork __P((struct vmspace *));
void vmspace_free __P((struct vmspace *));
void vnode_pager_setsize __P((struct vnode *, vm_ooffset_t));
void vnode_pager_umount __P((struct mount *));
void vnode_pager_uncache __P((struct vnode *, struct proc *));
void vslock __P((caddr_t, u_int));
void vsunlock __P((caddr_t, u_int, int));
void vm_object_print __P((/* db_expr_t */ int, boolean_t, /* db_expr_t */ int,
char *));
void vm_fault_quick __P((caddr_t v, int prot));
#endif /* KERNEL */
#endif /* !_VM_EXTERN_H_ */