I have been running into a serious problem with my Ubuntu 18.04 server.
I started noticing that there were serious slowdowns in the server and when I checked, CPU usage was all maxed to 100%. I began trying to diagnose the problem. The culprit seems to be ./kswapd0 which runs somewhat randomly every 10-30 seconds and maxes out the CPU for at most a couple minutes. Searching online I found this to be a common problem, and I tried all the suggested solutions including turning off swap completely and clearing dropping the cache.
However, I noticed something that I suspect may be the reason behind this issue and was hoping to get a professional opinion.
Here you can see the kswap process maxing out the CPU. Which many people have come across before.
Above is the result of running free --mega --wide.
I have 96 GB of RAM installed which should be more than enough for the processes running ,but what stood out to me is the 84 GB of cache being occupied. Could this massive cache be triggering the ./kswapd0? This was my theory, but dropping cache didn't improve the situation. It just steadily grew to be massive again.
I am at the end of my wits with this issue. Any information or guidance would be extremely appreciated. I can provide any additional information requested/necessary.
In case anyone is following and it can be useful for the future, the issue is not related to the cache. Having restarted the machine and having no processes running and only 1G out of 96G as cache, there is still 100% CPU usage for kswapd0.
