Re: [PATCH 1/3] rename cancel_rearming_delayed_work() to cancel_delayed_work_sync()

[Oleg Nesterov <oleg@tv-sign.ru>]

On 07/02, Jarek Poplawski wrote:
>
> On Sun, Jul 01, 2007 at 07:36:29PM +0400, Oleg Nesterov wrote:
> > Imho, the current naming of cancel_xxx workqueue functions is very confusing.
> > 
> > 	cancel_delayed_work()
> > 	cancel_rearming_delayed_work()
> > 	cancel_rearming_delayed_workqueue()	// obsolete
> > 
> > 	cancel_work_sync()
> > 
> > This looks as if the first 2 functions differ in "type" of their argument which
> > is not true any longer, nowadays the difference is the behaviour.
> > 
> > The semantics of cancel_rearming_delayed_work(dwork) was changed significantly,
> > it doesn't require that dwork rearms itself, and cancels dwork synchronously.
> > 
> > Rename it to cancel_delayed_work_sync(). This matches cancel_delayed_work() and
> > cancel_work_sync(). Re-create cancel_rearming_delayed_work() as a simple inline
> > obsolete wrapper, like cancel_rearming_delayed_workqueue().
> 
> I like the idea of this change, but have some doubt: "_sync"
> usually suggests the main difference from "" (or _nosync) is:
> _sync waits for something, while _nosync doesn't wait and
> instantly returns.

Yes, but we already have cancel_work_sync().

> Here it's a bit complicated: cancel_delayed_work() (so nosync),
> actually can wait a little too (on del_timer_sync). And
> cancel_rearming_delayed_work() is really more universal now,
> but still the main difference is this should be used with works
> that rearm (at least sometimes). If there is no rearming - no
> reason for this function (of course not forbidden too)  - and
> maybe it better helps to remember the difference?

There is a reason even if no rearming. We have a lot of

	cancel_delayed_work();
	flush_workqueue();

This should be converted to use cancel_delayed_work_sync().

Note also that both cancel_work_sync() and cancel_rearming_delayed_work()
can be used on any work (rearming or not) and both imply "flush".
I think the "_rearming" part of the name is very confusing, and a "good"
name should be consistent with cancel_work_sync() and cancel_delayed_work()
which we already have.

Oleg.