Re: [Rosegarden-devel] Crash and system lockup using hrtimer and alsa SEQ
On Thursday, May 13, 2010, Chris Cannam wrote: On Thu, May 13, 2010 at 3:51 AM, Geoff King gski...@gmail.com wrote: Hello, I just found a bug that crashes rosegarden and locks up my system. This happens when alsa seq is used with hrtimer setting in rosegarden. This is on Fedora 12 w CCRMA rt kernel and rosegarden 10.04.2. I had to hit the reset button to get out of it. To make it happen: 1) start module snd_hrtimer 2) start qjackctl/jackd running with midi driver set to SEQ. 3) start rosegarden and go into preferences and change midi timer preference from auto hrtimer. 4) system locked up.. Also locks up when starting rosegarden and these settings are saved. This sounds like a kernel bug rather than anything that Rosegarden can influence. Changing the timer setting in Rosegarden just makes Rosegarden tell the ALSA kernel layer to use a different timer, it makes no other difference to Rosegarden's own behaviour. It may be a kernel bug, but it is triggered by Rosegarden only, and not by other ALSA sequencer programs using this timer. For instance 1) start the module snd-hrtimer 2) start drumstick-sysinfo [1]. This program shows the hrtimer properties. 3) start drumstick-timertest. This program tests the best timer available, which is usually hrtimer. 4) If your ALSA drivers and library are modern enough (1.0.22 here), starting kmidimon, kmetronome, or kmid2 the system automatically selects hrtimer when it is available. This can be verified with this command while running the programs: $ cat /proc/asound/seq/timer There is a long history of unstable interactions between RT kernel patches and the different ALSA sequencer timers. I don't use a RT kernel, just the stock one provided by openSUSE, and Rosegarden consistently triggers the lockup. Regards, Pedro [1] http://sf.net/projects/drumstick/ -- ___ Rosegarden-devel mailing list Rosegarden-devel@lists.sourceforge.net - use the link below to unsubscribe https://lists.sourceforge.net/lists/listinfo/rosegarden-devel
Re: [Rosegarden-devel] Crash and system lockup using hrtimer and alsa SEQ
On Sat, May 15, 2010 at 2:17 PM, Pedro Lopez-Cabanillas pedro.lopez.cabanil...@gmail.com wrote: It may be a kernel bug, but it is triggered by Rosegarden only, and not by other ALSA sequencer programs using this timer. Interesting, I didn't know that. You have worked on the RG MIDI code and, of course, on drumstick -- do you have any feel for what the significant difference might be? I don't use a RT kernel, just the stock one provided by openSUSE, and Rosegarden consistently triggers the lockup. Yet if a non-RT thread in Rosegarden (and its MIDI thread is not real-time) can lock the system hard, the fault must be with the kernel -- no? None the less, it would be great to try to avoid provoking it if we can. Chris -- ___ Rosegarden-devel mailing list Rosegarden-devel@lists.sourceforge.net - use the link below to unsubscribe https://lists.sourceforge.net/lists/listinfo/rosegarden-devel
Re: [Rosegarden-devel] Crash and system lockup using hrtimer and alsa SEQ
On Saturday, May 15, 2010, Chris Cannam wrote: On Sat, May 15, 2010 at 2:17 PM, Pedro Lopez-Cabanillas pedro.lopez.cabanil...@gmail.com wrote: It may be a kernel bug, but it is triggered by Rosegarden only, and not by other ALSA sequencer programs using this timer. Interesting, I didn't know that. You have worked on the RG MIDI code and, of course, on drumstick -- do you have any feel for what the significant difference might be? Not specifically. As a workaround, I've commented out in AlsaDriver.cpp all the code between the lines 1515 and 1563 in setCurrentTimer(), deactivating the timer selection. It's superfluous here anyway, because I always use the hrtimer automatically. OTOH, the test program drumstick-metronome has code selecting the best timer available, and it doesn't lock the system when hrtimer is present. Regards, Pedro -- ___ Rosegarden-devel mailing list Rosegarden-devel@lists.sourceforge.net - use the link below to unsubscribe https://lists.sourceforge.net/lists/listinfo/rosegarden-devel
Re: [Rosegarden-devel] Crash and system lockup using hrtimer and alsa SEQ
On Thu, May 13, 2010 at 3:51 AM, Geoff King gski...@gmail.com wrote: Hello, I just found a bug that crashes rosegarden and locks up my system. This happens when alsa seq is used with hrtimer setting in rosegarden. This is on Fedora 12 w CCRMA rt kernel and rosegarden 10.04.2. I had to hit the reset button to get out of it. To make it happen: 1) start module snd_hrtimer 2) start qjackctl/jackd running with midi driver set to SEQ. 3) start rosegarden and go into preferences and change midi timer preference from auto hrtimer. 4) system locked up.. Also locks up when starting rosegarden and these settings are saved. This sounds like a kernel bug rather than anything that Rosegarden can influence. Changing the timer setting in Rosegarden just makes Rosegarden tell the ALSA kernel layer to use a different timer, it makes no other difference to Rosegarden's own behaviour. There is a long history of unstable interactions between RT kernel patches and the different ALSA sequencer timers. Chris -- ___ Rosegarden-devel mailing list Rosegarden-devel@lists.sourceforge.net - use the link below to unsubscribe https://lists.sourceforge.net/lists/listinfo/rosegarden-devel
