For some time now, Mail.app takes three minute or more to display its window, and for that interval, is labeled "not responding." There are several things that are related somehow:
- During that interval, fseventsd consumes 82%±3% of CPU.
- If we run
/usr/sbin/repairHomePermissions, Mail launches normally, but the fix only lasts a couple of days.
- If we rebuild mailboxes, it is not fixed; if we remove all the IMAP accounts and reinstall them, it is not fixed; but if we rebuild mailboxes after that reinstall, it is normal, but again, only for a day or two.
- If we remove everything from
/Library/LaunchDaemons, and reboot, it works normally. Did that today, so I don't know yet how long it will last.
Here is what was in LaunchDaemons:
I believe all of that has been around for longer than the problem. I recently got a new 2019 MBP with Catalina, upgraded to Big Sur, and used Migration Assistant to bring everything in from a 2012 MBP with Catalina. This problem never occurred on the old MBP, and I think (not certain) that it did not start immediately on the new one. I'm fairly sure I used it for weeks before this started happening.
Ideas? It's going to take two days to find out whether removing some LauchDaemon is a permanent fix, and if so, weeks to figure out which one. And it would still be a mystery how it interacts with permissions and mailboxes.
fseventsd is known to suck up CPU for Time Machine, but this problem has happened with Time Machine turned off and when the TM disks aren't even plugged in. And opening Mail should be making roughly the same disk actions each time it is launched.
Another oddity (but I think it's unrelated) is that Photos.app is allegedly using a lot of energy when the Dock,
ps -ef, and Activity Monitor all say Photos is not running. (Though sometimes,
photoanalysisd appears in Activity monitor briefly.)
UPDATE: After an O.S. update, most of the time, Mail opens instantly, and when it doesn't, the delay is only a few seconds (never the five-plus minutes from before). However, once in a while, for no obvious reason, a Finder action seems to take minutes!