Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [patch] cpusets, cgroups: disallow attaching kthreadd | From | Mike Galbraith <> | Date | Tue, 11 Oct 2011 18:57:16 +0200 |
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On Tue, 2011-10-11 at 16:08 +0200, Peter Zijlstra wrote: > On Mon, 2011-10-10 at 09:43 -0700, Tejun Heo wrote: > > > Yes, I think we need something like this. wq workers were using > > PF_THREAD_BOUND to prevent diddling from userland which made some > > unhappy. > > But that can be properly fixed. > > > Maybe we need a flag to properly indicate "don't diddle with > > this thread from userland"? But, then, mainline kernel wouldn't need > > the current PF_THREAD_BOUND at all. Peter, Steven, what do you think? > > Strict per-cpu affinity that is needed for correctness and disallows > sched_setaffinity() is something entirely different from not being > allowed to put something in a cgroup.
Agreed. The proposed patchlet is purely a practical matter.
> As to not allowing to put in a cgroup thing, is there anything other > than kthreadd for which we need to enforce that? So far I've mostly > treated it like: root can do stupid things, this is one of them, don't > do that then.
Yeah, that's the other side of the coin. The only thing I can think of justifying a response other than "well, gee, don't do that" is that Joe User shouldn't need to know or care about kernel workqueue details.
I don't know of anything other than kthreadd where moving it here, or over yonder matters one bit.
-Mike
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