Load average questions

[cdebackere]

Hi! 

The load average numbers  I get on one of my LM4s are a bit high at times, usually with peaks of CPU/IO 1.7 1.4 1.2
Usually it ranges from 0.8 to 1.2 with a memory usage of ~20%, will this affect the LM4s operation in a negative way? 

What are the recommended loads and what values should I strive for?

thats normal load, you can get peaks when you have a lot of telegrams on knx tp bus. some of our partners have lm with CPU/IO near 7 and it works.

normal CPU/IO is under 2.0

But if LM CPU load is high constantly LM will auto reboot.

Good to know! 


Thank you for the replies

a load > 1 doesn't mean that the cpu is occupied 100%. For that purpose you have to look at the cpu idle %. 
A load ~1 means that the cpu knows what to do and that there are several processes demanding cpu, and that some might have to wait a little (ms). But typically a load ~1 will still show that the cpu is idle for ~80%, so only occupied for 20%. That's because many of these processes only need the cpu for a fraction of the time.
If you know how to term into the device, then you can use top to see how much idle time is left for the cpu.

read this the get on top : http://blog.scoutapp.com/articles/2009/0...d-averages

If you have a badly running script, what can happen is that load ~1 and that cpu idle=0%. In that case your lm will be very slow and you should reboot the device. The problem is not always the script itself, but it's interaction with the lm system/drivers. We see this behaviour from time to time if a customer plugs in/out a sms/modem in the usb port. It causes a lot to happen in the background, with renumbering of ports numbers, but sometimes the script will still has an open socket to the old/wrong port. In 99% of the cases that goes well, closing the socket and reopening a new one, but in some rare cases it causes 100% cpu (0%idle)
In such case you can stop/start the script (if you know which one through a top command) or simply reboot the entire lm