MacOS – log file for App Nap

app-napconsolelogsmacos

I use a piece of specialty software that seems to be dealing badly with App Nap. Is there a way to retroactively list when App Nap acted on a specific process?

The Console log shows symptoms (Spindump reports when an app is throttled for excessive wakelocks or cpu use) but I can't find anything related to the third type of App Nap throttling (priority reduction), quoting from developer docs:

For any app that is not performing important user work, App Nap triggers a number of measures, including:

  • Priority reduction, which reduces the process priority of an app so that it receives a smaller share of available processor time

  • Timer throttling, which reduces the frequency with which an app’s timers are fired

  • I/O throttling, which reduces the rate at which an app can read or write data from a device while foreground apps need the device

Best Answer

app nap events are shown in the system.log (the easiest way to find them is to open up Console.app and look in All Messages).