KswapD0 use 100% CPU

After upgrde from 15.10 to 16.04, I noticed my netbook fan was constantly turning at full throtle. I checked the process mnitoor and noticed KswapD0 used 100% of one core.

What is the problem ? Because of this, my netbook is slow and i'm afraid of processor overheating.

This seems to be something that commonly (but not exclusively) pops up w/ low memory systems. You can check out the bug that's tracking this issue: Bug #1518457: kswapd0 100% CPU usage

There isn't an actual fix yet, but there are a couple workarounds that may fix the problem for you:

1. Add echo 1 > /proc/sys/vm/drop_caches to a regular crontab and/or run that command manually when kswapd acts up
2. Comment out line 2 in /lib/udev/rules.d/40-vm-hotadd.rules (see the bug link for more discussion)