On Tuesday 22 December 2009 15:21:04 Chris Radek wrote: > On Tue, Dec 22, 2009 at 11:51:31AM +0100, Michael Buesch wrote: > > Here's an interesting crash. > > It sometimes happens on EMC load. It's more or less reproducible by fireing > > up > > and shutting down EMC in a row. Something like 20 or 30 tries are sometimes > > required to reproduce. > > > > So, what is this? Well, I'm fairly certain that we have a race condition > > here. > > This crash does only seem to happen on SMP (I have two CPUs) when isolcpus > > is _not_ used. > > I'm using classic RCUs. > > > > > > [ 340.224299] Pid: 3359, comm: milltask Not tainted 2.6.29.6-rtai #2 > > GeForce7050M-M > > [ 340.254912] Pid: 3352, comm: hal_manualtoolc Tainted: G D > > 2.6.29.6-rtai #2 > > [ 340.255157] Pid: 2630, comm: Xorg Tainted: G D W 2.6.29.6-rtai #2 > > [ 340.255200] Pid: 3376, comm: rsyslogd Tainted: G D W 2.6.29.6-rtai > > #2 GeForce7050M-M > > [ 340.255714] Pid: 2630, comm: Xorg Tainted: G D W 2.6.29.6-rtai #2 > > GeForce7050M-M > > I see five panics here - three in programs unrelated to EMC. I think > you may just have a bogus kernel or rtai build.
Well, calling milltask and hal_manualtoolc being unrelated to EMC is... interesting. And 4 of the 5 oopses obviously are followup-oopses to the first one. It's also interesting to get an answer like "I think several people are running EMC on SMP systems.". That basically means I'm an idiot and I'm just too stupid to set it up properly. Well, ya know what? It is not the case. As I already said, this oops is reproducible and it happens when EMC is loaded. So there obviously _is_ _some_ interaction with EMC. Race conditions are hard to track down and if five people run a piece of software without a problem, that doesn't mean there are no races. Keep that in mind, please. Also notice that I did _not_ say that this is a bug in EMC. It could also be a bug in rtai or somewhere else. I'd like to get this tracked down, whether this is an EMC bug or not, because it does make EMC unusable for me (unless I use isolcpus). So any real ideas are greatly appreciated. I am running rtai 3.7.1 and latest EMC stable release. -- Greetings, Michael. ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
