Messages in this thread | | | Subject | Re: [RFC/RFT PATCH v3] sched: automated per tty task groups | From | Mike Galbraith <> | Date | Tue, 16 Nov 2010 08:41:48 -0700 |
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On Tue, 2010-11-16 at 16:03 +0100, Oleg Nesterov wrote: > 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.
Aha!
> Perhaps this deserve a commen (unless I missed something again). > > Mike, sorry for confusion.
Oh no, thank you. I hadn't figured it out yet, was going to go back and poke rt kernel with sharp sticks. (exit can be one scary beast)
-Mike
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