Messages in this thread | | | Date | Tue, 16 Nov 2010 16:03:20 +0100 | From | Oleg Nesterov <> | Subject | Re: [RFC/RFT PATCH v3] sched: automated per tty task groups |
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On 11/16, Mike Galbraith wrote: > > On Tue, 2010-11-16 at 14:04 +0100, Oleg Nesterov wrote: > > However, I must admit I dislike this check. Because, looking at this > > code, it is not clear why do we check PF_EXITING. It looks as if it > > is needed for correctness. > > Is _not_ needed I presume. > > I'll remove it, I'm not overly attached (a t t a..;) to it.
Argh!
I was wrong, it _is_ needed for correctness. Yes, it is always safe to read the pointer, but
> > Yes, sure, rq->lock should ensure signal->autogroup can't go away. > > (even if it can be changed under us). And it does, we are moving all > > threads before kref_put(). > > (yeah)
Exactly. And this means we can _only_ assume it can't go away if autogroup_move_group() can see us on ->thread_group list.
Perhaps this deserve a commen (unless I missed something again).
Mike, sorry for confusion.
Oleg.
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