Re: [PATCH 6/6] sched: disabled rt-bandwidth by default

Ingo Molnar
2008-08-19T11:12:21Z

* Ingo Molnar <mingo@elte.hu> wrote:

> The fixes look good to me, but this enabling of infinite RT task
> lockups is not an improvement.
>
> The thing is, i got far more bugreports about locked up RT tasks where
> the lockup was unintentional, than real bugreports about anyone
> _intending_ for the whole box to come to a grinding halt because a
> high-prio RT tasks is monopolizing the CPU.
>
> In fact there's only been this artificial test so far.
>
> So could you please just increase the chunking to 10 seconds or so,
> from the current 1 second? Anyone locking up the system for more than
> 10 seconds via an RT task has to deal with many other issues already.
>
> I.e. keep the system borderline debuggable (up to 10 seconds delays
> are _not_ nice so people will notice) - but it's still a marked
> improvement from completly locked up desktops.
>
> And those who really need longer than 10 second periods can set it
> higher, or even (if they want to live dangerously or run POSIX
> conformance tests) make it infinite (set it to -1) - and will have to
> deal with other things like the softlockup watchdog as well.
>
> Ok?

ok - i've queued the fixes up in tip/sched/rt (not in tip/sched/urgent
yet, they need a bit of test-time, but are potential v2.6.27 commits) -
see the shortlog below.

Ingo

------------------>
Ingo Molnar (1):
sched: set rt-bandwidth period from 1 second to 10 seconds

Peter Zijlstra (5):
sched: rt-bandwidth for user grouping interface
sched: rt-bandwidth accounting fix
sched: rt-bandwidth group disable fixes
sched: extract walk_tg_tree()
sched: rt-bandwidth fixes

kernel/sched.c | 215 +++++++++++++++++++++++++++++------------------------
kernel/sched_rt.c | 16 ++--
kernel/user.c | 4 +-
3 files changed, 129 insertions(+), 106 deletions(-)