The audio just glitched & dropped to silence a couple of days after the app was launched 'by hand' rather than via launchd, so I guess that rules out the thread priorities… *sigh* ;p (The app runs the music in a bar/nightclub, hence why the Mac was running for a couple of days) Michael07595247282 On 26 Dec 2015, at 23:10, Michael McNeela < email@hidden> wrote: OK, what about the audio realtime thread (during playback). It should be running at pri 97 -- is this true while the glitches are happening?
It’s indeed at 97 for both type of launch, but …the glitches tend to take a few hours/days of running to present themselves (!), so I’ll just try ditching launchd for a few days & see if the random glitching disappears (that’s how that attached ’things I’ve tried' matrix came to be :p)
(Thanks for the push in the potentially-right direction by the way!)
OK, what about the audio realtime thread (during playback). It should be running at pri 97 -- is this true while the glitches are happening?
Doug
# sent from my iPhone On Dec 26, 2015, at 14:40, Michael McNeela < email@hidden> wrote: Hey Doug
Your matrix makes me wonder: are you trying to play from a launchd daemon?
Yep; a launchd LaunchAgents daemon (i.e. not running as root)
Try taking an Instruments trace that captures thread scheduling activity. It sounds like the daemon is in a throttled state, which would show in a kernel or Instruments trace as having its threads running at a very low priority.
A short ~5 second trace seems to show the main thread via launchd consistently at priority 31, vs the main thread via ‘double-click to open’ at priority 46-47. (All other threads seem to have the same priorities regardless of how the app’s launched though)
Hi Michael,
Your matrix makes me wonder: are you trying to play from a launchd daemon?
Try taking an Instruments trace that captures thread scheduling activity. It sounds like the daemon is in a throttled state, which would show in a kernel or Instruments trace as having its threads running at a very low priority.
Doug
On Dec 26, 2015, at 10:11 , Michael McNeela < email@hidden> wrote:
Should you be curious, here’s what I’ve tried narrowing down so far;
<Screen Shot 2015-12-26 at 18.06.39 copy.jpeg>
On 26 Dec 2015, at 16:55, Michael McNeela < email@hidden> wrote:
Where are your video files ?
On the internal SSD
A late 2014 Mac mini (Macmini7,1), factory-configured to 2.6 GHz i5, 8GB RAM, 256GB SSD. The issue presents itself on three Macs of the same hardware configuration (bought & configured at roughly the same time), across 10.10.3, 10.10.5 and 10.11. I’m puzzled.
On 26 Dec 2015, at 16:50, Michael McNeela < email@hidden> wrote:
Thanks for the input everybody. I should clarify that I’m simply playing regular ol’ video files using Cocoa’s AVPlayer; nothing spectacular, and the video playback continues unaffected as the audio stutters and drops. It’s incredibly odd.
Oh, and audio is being outputted through the Mac’s headphone port; not external audio interface via USB/FireWire, etc.
I’ve stopped SSH attempts bumping the CPU, just in case they were related, but the issue persists, so now I’m at a loss.
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