On Mon, 2017-10-23 at 21:07 +0000, Paul E. McKenney wrote:
> From: Mark Rutland <mark.rutl...@arm.com>
>
> For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
> preference to ACCESS_ONCE(), and new code is expected to use one of the
> former. So far, there's been no reason to change most existing uses of
> ACCESS_ONCE(), as these aren't currently harmful.
>
> However, for some features it is necessary to instrument reads and
> writes separately, which is not possible with ACCESS_ONCE(). This
> distinction is critical to correct operation.
>
> It's possible to transform the bulk of kernel code using the Coccinelle
> script below. However, this doesn't pick up some uses, including those
> in <linux/average.h>. As a preparatory step, this patch converts the
> file to use {READ,WRITE}_ONCE() consistently.
>
> At the same time, this patch addds missing includes necessary for
> {READ,WRITE}_ONCE(), *BUG_ON*(), and ilog2().
>
> ----
> virtual patch
>
> @ depends on patch @
> expression E1, E2;
> @@
>
> - ACCESS_ONCE(E1) = E2
> + WRITE_ONCE(E1, E2)
>
> @ depends on patch @
> expression E;
> @@
>
> - ACCESS_ONCE(E)
> + READ_ONCE(E)
> ----
>
> Signed-off-by: Mark Rutland <mark.rutl...@arm.com>
> Cc: Johannes Berg <johannes.b...@intel.com>
Reviewed-by: Johannes Berg <johan...@sipsolutions.net>
Let me know if you want me to apply this, since I seem to be the
average.h maintainer :-)
johannes
