Messages in this thread | | | Date | Mon, 29 Mar 2010 14:51:38 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH tip/core/urgent] rcu: protect fork-time cgroup access |
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On Mon, Mar 29, 2010 at 11:42:55PM +0200, Peter Zijlstra wrote: > On Mon, 2010-03-29 at 14:34 -0700, Paul E. McKenney wrote: > > > And it appears that my patch is at best insufficient: > > http://paste.ubuntu.com/406189/ > > > > Left to myself, I would wrap copy_process() with rcu_read_lock(), > > but I would rather hear your thoughts before doing too much more > > semi-random hacking. ;-) > > Well, I don't think you can get away with that, copy_process() wants to > sleep on quite a few places ;-) Also, locks should be taken at the > smallest possible scope, unless we want to go back to BKL style > locking :-)
No argument here! ;-)
> As to that freezer splat, you'd have to chase down the cgroup folks, I'm > fully ignorant on that.
K, adding them to CC. The two splats are:
http://pastebin.ubuntu.com/406131/ http://paste.ubuntu.com/406189/
Some additional RCU protection is required, or perhaps some suppression of false positives. Thoughts?
> For the set_task_rq() one, I'm afraid someone (which again I'm afraid > will be me) will have to look into how the task_group muck ties into the > cgroup muck as I think the original authors of that ran off :/
Sigh!
Thanx, Paul
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