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freebsd/sys/vm/vm_extern.h
Alan Cox da61b9a69e Use sf_buf_alloc() instead of vm_map_find() on exec_map to create the
ephemeral mappings that are used as the source for three copy
operations from kernel space to user space.  There are two reasons for
making this change: (1) Under heavy load exec_map can fill up causing
vm_map_find() to fail.  When it fails, the nascent process is aborted
(SIGABRT).  Whereas, this reimplementation using sf_buf_alloc()
sleeps.  (2) Although it is possible to sleep on vm_map_find()'s
failure until address space becomes available (see kmem_alloc_wait()),
using sf_buf_alloc() is faster.  Furthermore, the reimplementation
uses a CPU private mapping, avoiding a TLB shootdown on
multiprocessors.

Problem uncovered by: kris@
Reviewed by: tegge@
MFC after: 3 weeks
2005-12-16 18:34:14 +00:00

99 lines
4.2 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.
* 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
* $FreeBSD$
*/
#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(struct thread *, void *, int *);
int madvise(struct thread *, void *, int *);
int mincore(struct thread *, void *, int *);
int mprotect(struct thread *, void *, int *);
int msync(struct thread *, void *, int *);
int munmap(struct thread *, void *, int *);
int obreak(struct thread *, void *, int *);
int sbrk(struct thread *, void *, int *);
int sstk(struct thread *, void *, int *);
int swapon(struct thread *, void *, int *);
#endif /* TYPEDEF_FOR_UAP */
int kernacc(void *, int, int);
vm_offset_t kmem_alloc(vm_map_t, vm_size_t);
vm_offset_t kmem_alloc_nofault(vm_map_t, vm_size_t);
vm_offset_t kmem_alloc_wait(vm_map_t, vm_size_t);
void kmem_free(vm_map_t, vm_offset_t, vm_size_t);
void kmem_free_wakeup(vm_map_t, vm_offset_t, vm_size_t);
void kmem_init(vm_offset_t, vm_offset_t);
vm_offset_t kmem_malloc(vm_map_t, vm_size_t, boolean_t);
vm_map_t kmem_suballoc(vm_map_t, vm_offset_t *, vm_offset_t *, vm_size_t);
void swapout_procs(int);
int useracc(void *, int, int);
int vm_fault(vm_map_t, vm_offset_t, vm_prot_t, int);
void vm_fault_copy_entry(vm_map_t, vm_map_t, vm_map_entry_t, vm_map_entry_t);
void vm_fault_unwire(vm_map_t, vm_offset_t, vm_offset_t, boolean_t);
int vm_fault_wire(vm_map_t, vm_offset_t, vm_offset_t, boolean_t, boolean_t);
void vm_forkproc(struct thread *, struct proc *, struct thread *, int);
void vm_waitproc(struct proc *);
int vm_mmap(vm_map_t, vm_offset_t *, vm_size_t, vm_prot_t, vm_prot_t, int, objtype_t, void *, vm_ooffset_t);
void vm_set_page_size(void);
struct vmspace *vmspace_alloc(vm_offset_t, vm_offset_t);
struct vmspace *vmspace_fork(struct vmspace *);
void vmspace_exec(struct proc *, vm_offset_t, vm_offset_t);
void vmspace_unshare(struct proc *);
void vmspace_free(struct vmspace *);
void vmspace_exitfree(struct proc *);
void vnode_pager_setsize(struct vnode *, vm_ooffset_t);
int vslock(void *, size_t);
void vsunlock(void *, size_t);
void vm_object_print(/* db_expr_t */ long, boolean_t, /* db_expr_t */ long,
char *);
int vm_fault_quick(caddr_t v, int prot);
struct sf_buf *vm_imgact_map_page(vm_object_t object, vm_ooffset_t offset);
void vm_imgact_unmap_page(struct sf_buf *sf);
void vm_thread_dispose(struct thread *td);
void vm_thread_dispose_altkstack(struct thread *td);
void vm_thread_new(struct thread *td, int pages);
void vm_thread_new_altkstack(struct thread *td, int pages);
void vm_thread_swapin(struct thread *td);
void vm_thread_swapout(struct thread *td);
#endif /* _KERNEL */
#endif /* !_VM_EXTERN_H_ */