For what it's worth, I installed a 3.19.3 kernel on a Ubuntu box thatformerly had a 3.16.32 kernel, and upon doing so saw this same behavior where I had not with the 3.16.32 kernel.
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On Thu, 2 Apr 2015, Rett Walters wrote:
Date: Thu, 2 Apr 2015 09:09:58 -0500 From: Rett Walters <rettw78@rtwnetwork.com> To: x2go-user@lists.x2go.org Subject: Re: [X2Go-User] x2goserver causes increase in ksoftirqd/x CPU usage
Mihai:
Yes - your right its the systemd unit called x2goserver, and it does appear to just start x2gocleansessions script. I will do some testing with older kernels to see if the problem is still present.
Thanks for the quick response.
Rett Walters
On Wed, Apr 1, 2015 at 3:11 PM, Mihai Moldovan <ionic@ionic.de> wrote:
Hi Rett,
On 01.04.2015 08:38 PM, Rett Walters wrote:
I have two machines running Archlinux with x2goserver running from arch repository packages that both exhibit abnormally high CPU usage in ksoftirqd/x (where x=the cpu core #). Here is an example top output showing the usage while idle - ksoftirqd is always the top user of CPU when the system is idle:
[...]
If I stop the x2goserver process, the ksoftirqd processes drop down to almost nothing. This seems to coincide with the 3.18 and 3.19 linux kernel series.
Could this be some sort of interaction between x2goserver and the kernel?
What process are you talking about specifically? "x2goserver" as such has no daemon process, aside from the "x2gocleansessions" script that is meant to cleanup after sessions terminated etc.
If you mean the daemon started via the x2goserver systemd unit, that's likely x2gocleansessions. It should be running consistently, but not cause high CPU stress due to the fact it's only running its main loop every two seconds. Maybe that needs to be raised, but I doubt it.
Did you ever see this behavior change, i.e., did older kernel versions not exhibit this behavior?
My Gentoo-based box running 3.19.0 doesn't show this problem. ksoftirq is, if at all, causing 0.5% CPU load with x2gocleansessions running. But my hardware is, naturally, different from your's, too.
Mihai
-- Rett Walters www.linuxpoweruser.com