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High CPU and disk usage for 1-2 minutes after login

Posted: Mon Sep 03, 2018 10:15 pm
by sumguy
Not sure when this started, but I'm getting high CPU usage, about 50% from Little Snitch Daemon plus another 25% or so from the kernel task, which lasts about a minute or two after startup. It seems to be reading something from the disk, as the "bytes read" in Activity monitor rises steadily to about 1.4 GB, until it stops.

If I start up and log in as a different user, it doesn't happen. Strangely, as that user I don't even see Little Snitch Daemon listed in Activity monitor, though Little Snitch Configuration says filtering is on. When I log out and log in again as my regular account, then it happens.

How can I fix this?

macOS Sierra 10.12.6, LS 4.1.3

PS, looks like someone else reported the same problem but got no reply:
viewtopic.php?f=1&t=11435&p=34629#p34629

Re: High CPU and disk usage for 1-2 minutes after login

Posted: Tue Sep 04, 2018 11:37 am
by christian
You may have subscribed to a rule group with lots of rules. We are currently working on optimizing this. Loading many rules and distributing the rule set among Little Snitch's component may take quite a while if there are several 1000 rules.

Re: High CPU and disk usage for 1-2 minutes after login

Posted: Tue Sep 04, 2018 4:22 pm
by sumguy
No, I don't have that many rules. I have 502 rules in total, including the built-in ones, I think that's a normal amount? This only started happening recently.

After deleting some old rules, I now have 436 rules, but it makes no difference. It still reads nearly a gigabyte and a half from disk. Actually it's usually 1.37 GB, the exact number that the other person mentioned.

Re: High CPU and disk usage for 1-2 minutes after login

Posted: Tue Sep 04, 2018 4:28 pm
by christian
While it's spinning, can you please make a sample of Little Snitch Daemon in Activity Monitor? The other thing that might happen is that Little Snitch Daemon is verifying the code signature of all your programs. This should only happen after an upgrade from Little Snitch 3, though.

Re: High CPU and disk usage for 1-2 minutes after login

Posted: Tue Sep 04, 2018 7:15 pm
by sumguy
Yes, it looks like it's doing a lot of code signing stuff. Here is the output from sample: https://0x0.st/svQb.txt

Re: High CPU and disk usage for 1-2 minutes after login

Posted: Tue Sep 04, 2018 7:25 pm
by christian
Yes. In order to symbolicate the sample: Which version of LS is this (preferably including build number)?

Re: High CPU and disk usage for 1-2 minutes after login

Posted: Tue Sep 04, 2018 7:55 pm
by sumguy
Little Snitch 4.1.3
Core System Version 5187
Kernel Version 5187

macOS Sierra 10.12.6

Re: High CPU and disk usage for 1-2 minutes after login

Posted: Wed Sep 05, 2018 3:07 pm
by christian
Thanks for reporting this!

Little Snitch is reading code signatures in order to determine the team names of your programs. There is a caching algorithm so that this info does not have to be read on every reboot or login, but due to a bug, the cache does not work for rules stored in the user's home directory (non-global and non-system rules). We will fix this, the fix should be in the next nightly release.

Re: High CPU and disk usage for 1-2 minutes after login

Posted: Wed Sep 05, 2018 4:03 pm
by sumguy
Ok, thanks!