Re: Where is RLIMIT_RT_CPU?

Lee Revell
2006-07-13T16:43:51Z

On Wed, 2006-07-12 at 10:23 +1000, Jean-Marc Valin wrote:
> Hi,
>
> I saw many references to RLIMIT_RT_CPU (e.g. in
> http://lwn.net/Articles/120797/ ) as a way of limiting the amount of CPU
> an unprivileged task can use at real-time priority. My understand was
> that the feature had been merged into 2.6.12 as part of Ingo's rt-limit
> patches. Unfortunately, I can't find any reference to that on my system
> (latest Ubuntu), so I'm wondering where it's gone. Has it been removed,
> renamed, ...? Considering that Ubuntu Dapper currently allows any user
> to make unlimited use of realtime scheduling, this feature would be
> really useful to prevent user apps from accidently crashing the system.

It was not merged.

This problem should be addressed by a userspace RT watchdog. Ubuntu
should not have shipped their system with unlimited non-root realtime
enabled and no watchdog.

Lee