No MIDI response after linuxsampler runs for a day

[sbenno]

hmm hard do say but if LinuxSampler had some kind of time related MIDI problem (eg problems start after several hours), if you restart LS
it should not give problems at least in the beginning. So my guess is the problem lies probably in the MIDI driver of your soundcard itself or some bad interaction between kernel and MIDI driver.
Did you test if other MIDI apps (some softsynth etc) experience the same kind of problems ?

[dgritter]

I have a strange problem with linuxsampler. I normally run with about 55 channels feeding two separate jack audio connections of 4 channels each. 4 midi input ports are connected to another application through the alsa snd_virmidi driver. When i first boot up the computer everything works fine and I can play sound on lots of channels simultaneously. But if I leave the computer running for a day (computer is remote from the organ console) and com back and play it again linux sampler's response to the mid channels will drop out for periods of up to 2 seconds. Specifically, the response of linuxsampler to midi messages on one of its four ports will stop, while the other ports continue to operate normally. This occurs every 15 or 20 seconds randomly on the four midi ports. Sound generation continues normally in linuxsampler if, for example, the response to the midi port stops when notes are already on. When response on the midi port resumes, it appears that a small number of queued up midi messages are responded to, but often note off messages are lost. I have connected kmidimon to the snd-virmidi ports feeding linuxsampler and have confirmed that the midi messages are coming out of snd-virmidi without interruption, so the problem appears to be linuxsampler related. However, i have tried stopping the linuxsampler process and the jack daemon, restarting them, restarting all the user space midi applications, and have not been able to correct the problem this way. The only way to correct the problem seems to be re-booting the computer. I am at a loss as to how to continue diagnosing this problem -- can anybody give suggestions?

I am using the latest version of Jackdmp, and latest versions of linuxsampler and libraries out of CVS as of about july 7. Everything is compiled for 64 bit mandriva linux 2008.1 using a patched pre-emptive realtime smp kernel from the mandriva contrib repository. System is running on an Athlon x2 system with 4meg Ram.

[dgritter]

yes, it is probably a kernel scheduler problem -- I can duplicate this behavior in other low priority (user space) applications that are not midi or sound related. -- I'll try using an earlier kernel.