Re: [PATCH] add unschedule_delayed_work to the workqueue API

[James Bottomley <James.Bottomley@SteelEye.com>]

On Mon, 2004-10-18 at 16:43, Andrew Morton wrote:
> James Bottomley <James.Bottomley@SteelEye.com> wrote:
> >
> > On Mon, 2004-10-18 at 16:26, James Bottomley wrote:
> > > On Mon, 2004-10-18 at 16:25, Andrew Morton wrote:
> > > > The usual way of doing this is:
> > > > 
> > > > 	cancel_delayed_work(...);
> > 
> > OK, found it in the headers, sorry .. it's not synchronous, so it can't
> > really be used in most of the cases where we use del_timer_sync().
> 
> cancel_delayed_work() will tell you whether it successfully cancelled the
> timer.  If it didn't, you should run flush_workqueue() to wait on the final
> handler.  The combination of the two is synchronous.

Right, but it potentially does too much work for my purposes.  I want to
cancel the work if it's cancellable or wait for it if it's already
executing.  I don't want to have to wait for all the work in the queue
just because the timer fired and it got added to the workqueue schedule.

> The missing link is cancellation of a delayed work which re-adds itself and
> where the calling code has no way of telling the handler to not re-arm
> itself.  There's a patch in -mm to add that function, but I don't like it.
> That's cancel_rearming_delayed_work.patch.

James