[PATCH] mm: pagefault_{disable,enable}()

Introduce pagefault_{disable,enable}() and use these where previously we did
manual preempt increments/decrements to make the pagefault handler do the
atomic thing.

Currently they still rely on the increased preempt count, but do not rely on
the disabled preemption, this might go away in the future.

(NOTE: the extra barrier() in pagefault_disable might fix some holes on
       machines which have too many registers for their own good)

[[email protected]: s390 fix]
Signed-off-by: Peter Zijlstra <[email protected]>
Acked-by: Nick Piggin <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Peter Zijlstra 2006-12-06 20:32:20 -08:00 • committed by Linus Torvalds
commit a866374aec
17 changed files with 88 additions and 62 deletions

View file

@ -56,7 +56,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
inc_preempt_count();
pagefault_disable();
if (op == FUTEX_OP_SET)
__futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
@ -88,7 +88,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
}
}
dec_preempt_count();
pagefault_enable();
if (!ret) {
switch (cmp) {