I am on openSuse with gnome and kernel 6.9.3-1. Around once during the day, my system runs a task ‘kworker btrfs-qgroup-rescan’ for around twenty minutes. It takes up one full core, consumes around 10 - 20 watts, drains the battery and heats up the device.
For some reason it also prohibits s2 idle sleep in my device, which is very annoying, as it sometimes continues running in my bag. My device model in particular has issues sleeping, that is not necessarily a fault of the kworker task, but the task causes the behavior, and if I could prohibit such long kworker tasks, sleeping would be less of an issue.
I already suspected that snapshots have something to do with it, so I deleted a bunch of old ones, but unfortunately this did not improve the situation. Can anyone tell me what kworker btrfs-qgroup-rescan does, why and when it is triggered and what influences its duration?