Re: [PATCH 12/13] workqueue: kill off ACCESS_ONCE()

From: Tejun Heo
Date: Tue Oct 10 2017 - 10:06:38 EST


On Mon, Oct 09, 2017 at 07:28:49PM +0100, Mark Rutland wrote:
> 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 handle comments, leaving references
> to ACCESS_ONCE() instances which have been removed. As a preparatory
> step, this patch converts the workqueue code and comments to use
> {READ,WRITE}_ONCE() consistently.
...
> Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

If you want me to route it through the workqueue tree, please let me
know.

Thanks.

--
tejun