On Wed, 29 Jun 2016 15:59:59 +0200, Baptiste Jonglez wrote: > > Hello Takashi, > > On Wed, Jun 29, 2016 at 03:39:37PM +0200, Takashi Iwai wrote: > > > Do you think the problem is likely to come from an incorrect API usage > > > from the application? Knowing this would significantly narrow down the > > > search, because the problem could also come from within alsa itself. > > > > > > The callling code from the application is quite complex, see here: > > > > > > https://github.com/savoirfairelinux/ring-daemon/blob/master/src/media/audio/alsa/alsalayer.cpp > > > > > > In particular, the assertion is triggered by the call to > > > snd_pcm_avail_update() at line 694 (see the stack trace below). > > > > I have too little time to investigate on this issue, but judging from > > the fact that there has been no such a report until now, I guess it's > > specific to your code. But I can't say sure, of course. > > Well, I did find other projects having this issue: > > https://aur.archlinux.org/packages/zoom/#comment-544696 > http://ubuntuforums.org/showthread.php?t=2248373 > https://github.com/js-platform/node-webrtc/issues/110 > https://fedorahosted.org/fldigi/ticket/70 Oh well. They have been never reported to upstream... In anyway, your report is the first one, and with a stack trace. > Although in most of these cases, the issue seems 100% reproducible > (e.g. crash at startup). In our case, the assertion failure only happens > when there is significant CPU load. > > > Is the relevant code path accessed concurrently? The possible race is > > the first suspect I'd always think of in such a case. > > Good idea, I will check. Given it happens when the CPU is loaded, my > guess is that "something" is done too late, which means that it works on > "invalidated" data (this is all very vague, sorry). > > Would you know a simple program using alsa-lib for sound capture, with > which I could try to reproduce? arecord? But it's no multi-thread, so not suitable for the concurrency tests. How is your PCM plugin setup? Is softvol over dmix? Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
