On Mon, 7 Jan 2008 12:09:04 +0100 Ingo Molnar <[EMAIL PROTECTED]> wrote:
> > > > This causes a practical problem. When a runaway real-time task is > > > eating 100% CPU and we attempt to put the CPU offline, sometimes we > > > block while waiting for the creation of the highest-priority > > > "kstopmachine" thread. > > sched-devel.git has new mechanisms against runaway RT tasks. There's a > new RLIMIT_RTTIME rlimit - if an RT task exceeds that rlimit then it is > sent SIGXCPU. Is that "total RT CPU time" or "elapsed time since last schedule()"? If the former, it is not useful for this problem. > there's also a new group scheduling extension that is driven via a > sysctl: > > /proc/sys/kernel/sched_rt_ratio > > this way if a user has a runaway RT task, other users (and root) will > still have some CPU time left. (in Peter's latest patchset that is > replaced via rt_runtime_ns - but this is a detail) Doesn't this make the RT task non-RT? Would need to understand more details to tell. > so instead of the never-ending arms race of kernel thread priorities > against RT task priorities, we are going towards making RT tasks safer > on a policy level. > > Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
