Hi Philippe, I have attached this patch to my application. So far it looks really good. However, I leave my test running to be sure that it works.
Regards Mathias > On Fri, 2007-07-20 at 14:16 +0200, Philippe Gerum wrote: > > On Fri, 2007-07-20 at 13:54 +0200, M. Koehrer wrote: > > > Hi Philippe, > > > I left my test running for a couple of hours - no freeze so far... > > > > > > However, I have to do some other stuff on this machine, I have to stop > the test now... > > > > > > > Ok, thanks for the feedback. I will send an extended patch later today, > > so that you could test it on a longer period when you see fit. > > It took me a bit longer than expected, but here is a patch which > addresses all the pending issues with RPI, hopefully (applies against > 2.3.1 stock). > > The good thing about Jan grumbling at me, is that this usually makes me > look at the big picture anew. And the RPI picture was not that nice, > that's a fact. > > Beside the locking sequence issue, the ex-aequo #1 problem was that CPU > migration of Linux tasks causing a RPI boost had some very nasty > side-effects on RPI management, and would create all sort of funky > situations I'm too shameful to talk about, except under the generic term > of "horrendous mess". > > Now, regarding the deadlock issue, suppressing the RPI-specific locking > entirely would have been the best solution, but unfortunately, the > migration scheme makes this out of reach, at least without resorting to > some hairy and likely unreliable implementation. Therefore, the solution > I came with consists of making the RPI lock a per-cpu thing, so that > most RPI routines are actually grabbing a _local_ lock wrt the current > CPU, those routines being allowed hold the nklock as they wish. When > some per-CPU RPI lock is accessed from a remote CPU, it is guaranteed > that _no nklock_ may be held nested. Actually, the remote case only > occurs once, in rpi_clear_remote(), and all its callers are guaranteed > to be nklock-free (a debug assertion even enforces that). > > For the migration issue, the RPI transitions have been ironed out to > make sure we deal properly with all the subtleties of the Linux load > balancer. > > Mathias, please let me know if the attached patch improves the situation > on your side. > > -- > Philippe. > > > -- Mathias Koehrer [EMAIL PROTECTED] Viel oder wenig? Schnell oder langsam? Unbegrenzt surfen + telefonieren ohne Zeit- und Volumenbegrenzung? DAS TOP ANGEBOT FÜR ALLE NEUEINSTEIGER Jetzt bei Arcor: günstig und schnell mit DSL - das All-Inclusive-Paket für clevere Doppel-Sparer, nur 34,95 inkl. DSL- und ISDN-Grundgebühr! http://www.arcor.de/rd/emf-dsl-2 _______________________________________________ Xenomai-core mailing list [email protected] https://mail.gna.org/listinfo/xenomai-core
