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Subject: Re: RT scheduling and a way to make a process hang, unkillable
From: Peter Zijlstra <peterz@infradead.org>
To: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Corey Hickey <bugfood-ml@fatooh.org>, linux-kernel@vger.kernel.org,
       Bharata B Rao <bharata@linux.vnet.ibm.com>,
       Balbir Singh <balbir@in.ibm.com>,
       Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
       Ingo Molnar <mingo@elte.hu>, mtk.manpages@gmail.com,
       Alan Cox <alan@lxorguk.ukuu.org.uk>
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Date: Mon, 23 Feb 2009 12:59:56 +0100
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On Mon, 2009-02-23 at 17:15 +0530, Dhaval Giani wrote:
> On Tue, Feb 17, 2009 at 12:15:39PM +0100, Peter Zijlstra wrote:
> > On Tue, 2009-02-17 at 15:45 +0530, Dhaval Giani wrote:
> > 
> > > sched: Don't allow setuid to succeed if the user does not have rt bandwidth
> > > 
> > > Corey Hickey reported that on using setuid to change the uid of a
> > > rt process, the process would be unkillable and not be running.
> > > This is because there was no rt runtime for that user group. Add
> > > in a check to see if a user can attach an rt task to its task group.
> > 
> > This looks good to me.
> > 
> > Does anybody object to the -ENOSPC return value? Should we introduce
> > -ENOTIME for that?
> > 
> > Michael, Alan?
> > 
> 
> Hi,
> 
> Any comments on which return value to return? Should we introduce
> -ENOTIME?
> 
> Corey mentioned he found ENOSPC confusing.

I'd say go for the ENOTIME thing.