On 03/04/20(Fri) 09:40, Martin wrote: > Hello, Martin. > [...] > When I run mpv and try to watch 720p video. In case of stutters after some > time of watching audio flow desyncronized with video flow and mpv show video > FPS/2 rate afterwards. > > Each time of stutter mpv increase 'Dropped' like > > A-V: 0.000 Dropped: 58++ Cahce: 1378s+154MB
Ok so the piece of software is mpv(1). > I did ktrace for mpv process. I run and see by 'kdump -H ktrace.out' that it > has > one process ID and / mostly one-three thread used. > But sometimes (assuming in stutter times) it jumping against treads with > different numbers. Could you upload the output of kdump -H somewhere such that I could look at it or compress it and send it? > Yes, IPI increased to 900-1000 when stutter appears. > > I'm going to disable step-by step each 'out of the box' software to determine > the reason. Am I right doing this way? I believe it isn't necessary. From what you are saying it seems that mpv(1) alone is the piece of software exposing the issue. There are multiple possible reasons for IPIs, but if the high rate you're seeing is exposed by mpv(1), it would suggest they are related to scheduling. By looking at the output of ktrace(1) we should have a better understanding of what is happening in userland. I'd suggest you also do the btrace(8) profiling so we can see which code path in the kernel is responsible for the IPIs. These should allows us to work with facts and not guesses. Thanks for your efforts, Martin
