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

From: Mark Rutland
Date: Tue Oct 10 2017 - 12:23:14 EST


On Tue, Oct 10, 2017 at 07:06:29AM -0700, Tejun Heo wrote:
> 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>

Thanks!

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

I'm not sure what the plan is for merging just yet, but I will let you
know as soon as that's figured out.

Thanks,
Mark.