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authorRoland McGrath <roland@gnu.org>1999-07-11 11:44:31 +0000
committerRoland McGrath <roland@gnu.org>1999-07-11 11:44:31 +0000
commit57a491d1055bec7c49bd5c0149170b576b38fd7b (patch)
tree745af60a433b5585c65ae1764c3df9e17fb487fa /sysdeps/mach
parent5ef2d37b330420c89cd476afa83ca5a839094796 (diff)
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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.
Diffstat (limited to 'sysdeps/mach')
-rw-r--r--sysdeps/mach/hurd/mmap.c23
1 files changed, 21 insertions, 2 deletions
diff --git a/sysdeps/mach/hurd/mmap.c b/sysdeps/mach/hurd/mmap.c
index 8b4c3455c1..403678af9c 100644
--- a/sysdeps/mach/hurd/mmap.c
+++ b/sysdeps/mach/hurd/mmap.c
@@ -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;