On Wed, Oct 17, 2018 at 09:47:05PM -0700, David Miller wrote:
> From: Debabrata Banerjee <dbane...@akamai.com>
> Date: Fri, 12 Oct 2018 12:59:29 -0400
>
> > @@ -826,7 +826,10 @@ static void netpoll_async_cleanup(struct work_struct
> > *work)
> >
> > void __netpoll_free_async(struct netpoll *np)
> > {
> > - schedule_work(&np->cleanup_work);
> > + if (rtnl_is_locked())
> > + __netpoll_cleanup(np);
> > + else
> > + schedule_work(&np->cleanup_work);
> > }
>
> rtnl_is_locked() says only that the RTNL mutex is held by someone.
>
> It does not necessarily say that it is held by the current execution
> context.
>
> Which means you could erronesly run this synchronously when another
> thread has the RTNL mutex held, not you.
>
> I'm not applying this, sorry.
>
Agreed, this doesn't make sense. If you want a synchronous cleanup, create a
wrapper function that creates a wait queue, calls __netpoll_free_async, and
blocks on the wait queue completion. Modify the cleanup_work method(s) to
complete the wait queue, and you've got what you want.
Neil
