Re: 2.6.28, limiting cpu time doesn't work

[Ingo Molnar <mingo@elte.hu>]

* Oleg Nesterov <oleg@redhat.com> wrote:

> On 03/23, Peter Lojkin wrote:
> >
> > Oleg Nesterov wrote:
> >
> > > Found this message on http://bugzilla.kernel.org/show_bug.cgi?id=12911 ...
> > >
> > > I _think_ posix_cpu_timers_init_group() is not right, it should copy
> > > cputime_expires->prof_exp.
> > >
> > > Peter, any chance you can test the (uncompiled/untested) patch below?
> >
> > yes, with this patch 2.6.28.8 works as expected, thank you!
> 
> Great, thanks!
> 
> > if you need to test any more patches on the subject i'm ready to do it.
> > regression test system for our project depends on ability to limit cpu time,
> > so it's major problem for us...
> 
> I am not sure what should we do, this needs more discussion.
> 
> Probably the most simple patch for -stable and 2.6.29 is below.
> (with this patch we don't even need update_rlimit_cpu(), afaics).
> 
> Oleg.
> 
> --- a/kernel/posix-cpu-timers.c
> +++ b/kernel/posix-cpu-timers.c
> @@ -1263,7 +1263,8 @@ static inline int fastpath_timer_check(s
>  		if (task_cputime_expired(&group_sample, &sig->cputime_expires))
>  			return 1;
>  	}
> -	return 0;
> +
> +	return sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY;

Once this version of the patch is confirmed to fix the bug, please 
send a full patch with a full changelog, SOB, Reported-by and 
Tested-by lines.

Thanks,

	Ingo