[ag-automation] Kernel Summit / RT-Preempt activities in mainline

[Markus Wild]

Thanks Robert for the hint.

Yes indeed, the RT Preempt activities of Thomas and Ingo are looking
very promissing.;-)

Robert Schwebel schrieb:
> Collegues,
> 
> Just a short notice that Linux Weekly News (LWN): 
> 
> 	http://lwn.net/
> 
> has a detailed report about the Linux Kernel Summit that took place in
> Ottawa this week. It is in the 20 July edition, currently only available
> for paying customers. If you don't happen to be one of them, you'll have
> to wait for a week or so before it is available to the general public.
> Anyway, consider a subscription, because this is one of the highest
> quality news ticker for Linux technology activities.
> 
> The most important bits:
> 
> - Thomas Gleixner reported about the state of the timer development,
>   especially about the dynamic tick code (dyntick): it changes the
>   current "one timer tick per HZ" behaviour to "one timer tick if
>   necessary", resulting in something like 1.5 ticks per second on a
>   "usual" system. Linus noted that there's another dyntick
>   implementation for ARM, but it looks like the ARM maintainers are
>   willing to adopt the "generic" variant. So Linus sees no reason not
>   to merge the dyntick code - good news for the automation folks.
> 
> - Ingo Molnar noted that the current RT-Preempt patch decreased to
>   something like 700 kB - compared to the 1.6 MB of the still available
>   latest 2.6.17-rt7 patch: this shows that tglx and Ingo are doing
>   a very successful job in bringing HRT into the mainline. The "big"
>   problems are obviously already being resolved, the report talks
>   about one outstanding issue: recovery after a realtime task has
>   run out of control. The proposed solution is a soft lock detector.
> 
> - The patches currently remaining in -rt are mostly hrtimers and
>   sleeping locks. Linus seems to have agreed to merge the sleeping locks
>   into mainline. Sleeping locks are important to have only a small
>   ammount of kernel code to be audited for HRT. 
> 
> So the overall situation seems to be excellent! It currently remains
> unclear what the state of the architectures (ARM, PPC) currently is, so
> stay tuned until after the first 2.6.18-rc based preempt rt patch will
> be out. 
> 
> Regards,
> Robert 
-- 

Kind regards

Markus Wild

Open Source Automation Development Lab (OSADL)

Homagstraße 3 - 5
D - 72296 Schopfloch
Tel.: +49 (74 43) 13-2968
Fax: +49 (74 43) 13-8-2968

markus.wild at osadl.org
http://www.osadl.org