Usage time tracking is being killed by jetsam

Brief & History

Since iOS 17.4 and up we experience a lot of flakyness when it comes to DeviceActivity event thresholds. After a lot of testing and investigations inside system logs and filing countless bug reports we found a reproducible way why the event thresholds are not getting properly called.

Findings

Apparently when the device reaches near to max memory something called jetsamkills processes left and right.

This means that the UsageTrackingAgent that (we think) is responsible for tracking the usage time of the device gets killed and doesn't recover until significant memory is freeing up on the device.

How to test it yourself

  1. Use a slightly older device with ~ 3 or 4 GB of RAM
  2. Open a game or two that is meomry intensive (like Fishing Clash, yes..) and observe

In the console logs you see something that only happens then:

Process UsageTrackingAgent [39307] killed by jetsam reason highwater

This happens often but recovers itself when the UsageTrackingAgent exceeds their 6MB memory limit. Yet the log looks like this:

Process UsageTrackingAgent [39307] killed by jetsam reason per-process limit

Once you kick the game, the memory is free and sometimes the event thresholds are calling in again.

Defeating the purpose

However this defeats the purpose of tracking usage time and shielding perhaps the playing app from being played after a certain amount of time!

Feedback Assistant Ticket

Here is the ticket with sysdiagnose, step by step and more information: FB13884981

Please fix this ASAP, this is such a pain for production users and their kids EVERY DAY.

Answered by Engineer in 791134022

I understand, and this is an issue we're aware of (FB13884981), but we're not aware of any recommended workaround so far. If you find something that helps you avoid the issue, please share it with the community by coming back and posting it here.

I understand, and this is an issue we're aware of (FB13884981), but we're not aware of any recommended workaround so far. If you find something that helps you avoid the issue, please share it with the community by coming back and posting it here.

Usage time tracking is being killed by jetsam
 
 
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