I have an app that is requesting a BGProcessingTaskRequest -- this is the type of background activity that is encouraged to use if you have a process that is long running and advertised to even be able to retrain a machine learning model.
My background processing generally uses a DispatchQueue.global(qos: .background)) but I can't completely control this as I also for instance use a private Core Data background context.
However, my process gets killed due to cpu usage.
Event: cpu usage
Action taken: Process killed
CPU: 48 seconds cpu time over 55 seconds (87% cpu average), exceeding limit of 80% cpu over 60 seconds
CPU limit: 48s
Limit duration: 60s
CPU used: 48s
CPU duration: 55s
Duration: 55.24s
Duration Sampled: 40.95s
Steps: 22
Why is iOS imposing a CPU limit when the process is advertised as "A request to launch your app in the background to execute a processing task that can take minutes to complete.". The device was also plugged in during the crash.
The high cpu usage obviously is on purpose and also happens in a low-level Accelerate framework operation that I could not even throttle if I wanted to.
Any idea what I am doing wrong?