On 3/9/21 6:55 PM, Kevin Locke wrote: > With kernel 5.12-rc2 (and torvalds/master 144c79ef3353), if mpd is > playing or paused when my system is suspended-to-ram, when the system is > resumed mpd will consume ~200% CPU until killed. It continues to > produce audio and respond to pause/play commands, which do not affect > CPU usage. This occurs with either pulse (to PulseAudio or > PipeWire-as-PulseAudio) or alsa audio_output. > > The issue appears to have been introduced by a combination of two > commits: 3bfe6106693b caused freeze on suspend-to-ram when mpd is paused > or playing. e4b4a13f4941 fixed suspend-to-ram, but introduced the high > CPU on resume. > > I attempted to further diagnose using `perf record -p $(pidof mpd)`. > Running for about a minute after resume shows ~280 MMAP2 events and > almost nothing else. I'm not sure what to make of that or how to > further investigate. > > Let me know if there's anything else I can do to help diagnose/test. Thanks for the report, let me take a look and try and reproduce (and fix) it. I'll let you know if I fail in reproducing and need your help in testing a fix! -- Jens Axboe
