MacOS – Excessive CPU usage from sysmond

cpumacos

Does anyone know what the sysmond application does on OS X? Lately it has been taking about 25-30% cpu constantly for no apparent reason.

Things I've tried so far:

Reboot
SMC reset
PRAM reset
Starting up in safe mode (sysmond also sucks up resources there)
Filesystem check (except for the regular incorrect directory count, no errors or whatever)

For the time being I've just disabled the sysmond plist but I guess it's not completely useless so I'm wondering what it's supposed to do and whether disabling is harmful 😉

Best Answer

What sysmond does on OS X

Watching the CPU usage of sysmond through Activity Monitor is pointless! It turns out that sysmond process is what Activity Monitor uses to get it's readings.

So if sysmond is using lots of CPU, just kill activity monitor for it to stop.

Warning

Increasing the update interval for Activity Monitor dramatically increases the CPU load, that's why I initially never noticed it and see it a lot more right now.

Related Solutions

MacBook Pro – Fix for Not Sleeping When Lid is Closed

A lack of wake reason entries suggests your Mac is never fully sleeping. The sleep mechanism has started but never completes.

Use the following Terminal command to view a detailed log showing your Mac's power history:

pmset -g log

You will see a list of entries in form:

 * Domain: applicationresponse.slowresponse
 - Message: PMConnection AirPort configd plug-in com.apple.powermanagement.applicationresponse.slowresponse 1399 ms
 - Time: 13/03/2012 12:27:53 CET 
 - Signature: AirPort configd plug-in
 - UUID: AB482838-2D6E-0000-0000-14BF53E20000
 - Result: Noop
 - Response time (ms): 1399

Look out for applications that may be keeping your Mac awake and active. Applications and other processes can keep your Mac awake if they are providing a service, such as file sharing or remote access. However, processes should be forced asleep after 30 seconds on lid close.

The behaviour you are seeing suggests a kernel extension or IOKit problem. User level processes can not block sleep when instigated by the user.

Do you have any utilities installed that install kernel extensions (kext)? These might include screen recording or audio capture tools; utilities than need low level access to your Mac.

MacOS Performance – High CPU Usage by Process ‘ubd’

By observing log messages in ~/Library/Logs/Ubiquity/<my username>/, I realized that Ubiquity (iCloud process) kept trying to create a file in a folder that doesn't exist:

ubiquity log

I opened up the Terminal and created this directory and its parent directories up to .ubd:

cd ~/Library/Mobile\ Documents/
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Then I changed the newly created directories' owner from root to myself:

cd ../..
sudo chown -R <my username> .ubd/

The fan turned silent instantly.