Re: [PATCH 2/5] rcu: don't check ->donelist in __rcu_pending()

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

Srivatsa Vaddagiri wrote:
> 
> On Mon, Jan 09, 2006 at 11:59:33AM -0800, Paul E. McKenney wrote:
> > Hmmm...  So your thought is that __rcu_offline_cpu() moves nxtlist and
> > curlist, but not donelist, but then returns to rcu_offline_cpu(), which
> > might well do the tasklet_kill_immediate() before the tasklet completed
> > processing all of donelist.
> >
> > Seems plausible to me.  If true, your patch adding the following statement
> > to the ed of __rcu_offline_cpu seems like a reasonable fix:
> >
> >       rcu_move_batch(this_rdp, rdp->donelist, rdp->donetail);
> >
> > Vatsa, is there something that Oleg and I are missing?
> 
> I think this should take care of the CPU Hotplug bug, with the caveat
> that the callbacks on ->donelist will wait for additional grace period before
> being invoked (which seems ok).
> 
> Oleg, do you want to resend the patch after some testing?

Sure. The problem is that I have no idea how to test this change.
However, the patch seems "obviously correct", so I am sending it.

Srivatsa, I am sorry, I forgot to add you on CC: list while re-sending
these cleanups. I hope you can see them on lkml.

Oleg.