Is Watchdog Timeout and Expiration the same thing?

TidBITS Talk
1

I think my Mac (M2 Air, 2022; OS 26.3) is smarter than I give it credit for…

Had just downloaded TurboTax to get started on the ’25 return, renaming and sorting and filing documents in Finder, when the spinning pizza appeared when trying to drag and drop a file from one Finder tab to another (it’s a bit past lunchtime and I skipped, so maybe… ;-). That cleared after about 20 seconds and within minutes I tried another drag and drop but this time the pizza spun for a good minute then Mac rebooted itself.

After reboot a Problem Report for macOS window was there, the only thing listed in Details and Configuration was “S0CD report detected: (AP watchdog expired)”. I tried to click Send to Apple but nothing visible happened.

Searched the phrases online and in TBT and came up with references to watchdog “timeout”, but this one says ‘“expired”.

Macworld forums show this error dating back couple of years, some posters there and in Apple Discussions saying it’s hardware related and one should run Apple Diagnostics.

Mac is stable for now and I’ve done full backups. Should I be searching for expire or timeout? or some other keywords? Anyone happen to know for sure what this is, transient or definite sign of impending doom?

Or :grinning_face_with_smiling_eyes: is Mac telling me to eat lunch and do taxes later? :squinting_face_with_tongue:

2

“Once is a fluke, twice is a trend”

2 Likes
3

I don’t think there’s a preferred term between “timeout” or “expired”, they basically mean the same thing - the WDT stopped getting reset on schedule & reset the system.

As for what’s causing it, it could be anything that locks up your Mac & stops the OS from periodically resetting the watchdog timer; could be hardware, could be software. Not an easy thing to debug, unfortunately. But if it’s only happened once I wouldn’t worry about it.

1 Like
4

Thanks @Gryphon , that’s exactly the context I needed. I hadn’t rebooted the MBAir for… a while, many days at least. I have noted in the past it gets wonky if it goes to long without it. Maybe that was it.

1 Like