Activity Monitor itself, any time I open it, lags horribly and shows a spinning "beach ball." It continues to lag horribly until I right click on it in the Dock, wait several seconds for the context menu to appear, and choose "Force Quit."

No other application is giving me trouble, just Activity Monitor.

I could probably fix this by restarting the computer, however (a) I don't want to restart the computer (I have a couple VMs running and other things I'd rather not close down) and (b) I'm very curious to see more in detail what could be causing this.

(I'm a sysadmin by trade, so it should go without saying that I enjoy troubleshooting and tracing down the causes of computer behavior.)

Is this a bug in Activity Monitor, perhaps, or what?

So my question, essentially, is "What could be going on here?" but to state it more precisely a few different ways:

  1. What steps could I take to trace down more precisely why Activity Monitor is slow/laggy? Or,
  2. What steps could I take to diagnose and possibly fix this particular slowness without shutting down the computer? And on a side note,
  3. What information (logs, diagnostics, command output, etc.) would I need to provide to Apple to file this as a bug report?

I'm running 10.11.6.

  • This - apple.stackexchange.com/questions/51389/… has some AM substitute suggestions; not sure which can install without a reboot, but might be something there worth looking at. Or htop - apple.stackexchange.com/questions/76638/… – Tetsujin Jan 18 '17 at 7:56
  • Do you know yet if this is a user-specific issue or system-wide? If you have another user account you should log in to it and see if the issue occurs. This would narrow it down much further. Unfortunately my other suggestion would be attempting to run Activity Monitor in Safe Mode to see if the issue occurs there as well, but that requires restarting your system. – NYKg Jan 19 '17 at 4:10
  • @NYKg, interesting idea, but I have no other user account on this computer. (I'd rather not make one just for this purpose, although I might if no other answers/comments appear.) – Wildcard Jan 19 '17 at 4:14
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    I have the same problem today, after 14 months of purchase. Should mention, I'm a developer and therefore probably stress my system way more than average, installing all kinds of stuff. However, using other apps and command line tools for measuring performance on CPU, memory, I/O, shows nothing out of the ordinary. Just, Activity Monitor. Rebooting helps, but does not restore, if you get what I mean. If I find no solution, I will do what I've never done on a mac since I became a user 9 years ago. Reinstall. At least it will tell me, if the problem persists, might not be software. – Wrench Apr 13 '17 at 1:19
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    @Wrench, if you do reach that point please comment whether it helped or not. :) I'm inclined to think there's a bug in Activity Monitor. Are you also running 10.11.6? – Wildcard Apr 13 '17 at 2:00