1999-07-11 Roland McGrath <roland@baalperazim.frob.com>

* sysdeps/mach/hurd/mmap.c (__mmap): Short-circuit to vm_allocate 
for MAP_ANON, prot==PROT_READ|PROT_WRITE.
This commit is contained in:
Roland McGrath 1999-07-11 11:44:31 +00:00
parent 5ef2d37b33
commit 57a491d105
1 changed files with 21 additions and 2 deletions

View File

@ -1,4 +1,4 @@
/* Copyright (C) 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
/* Copyright (C) 1994, 1995, 1996, 1997, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@ -40,10 +40,29 @@ __mmap (__ptr_t addr, size_t len, int prot, int flags, int fd, off_t offset)
vm_address_t mapaddr;
vm_size_t pageoff;
mapaddr = (vm_address_t) addr;
if ((flags & (MAP_TYPE|MAP_INHERIT)) == MAP_ANON
&& prot == (PROT_READ|PROT_WRITE)) /* cf VM_PROT_DEFAULT */
{
/* vm_allocate has (a little) less overhead in the kernel too. */
err = __vm_allocate (&mapaddr, len, !(flags & MAP_FIXED));
if (err == KERN_NO_SPACE && (flags & MAP_FIXED))
{
/* XXX this is not atomic as it is in unix! */
/* The region is already allocated; deallocate it first. */
err = __vm_deallocate (__mach_task_self (), mapaddr, len);
if (!err)
err = __vm_allocate (&mapaddr, len, 0);
}
return err ? (__ptr_t) (long int) __hurd_fail (err) : (__ptr_t) mapaddr;
}
pageoff = offset & (vm_page_size - 1);
offset &= ~(vm_page_size - 1);
mapaddr = (vm_address_t) addr;
if (flags & MAP_FIXED)
{
/* A specific address is requested. It need not be page-aligned;