Ubuntu
gnome-system-monitor package

Exeptionally high CPU consumption

Bug #706073 reported by Denys Rtveliashvili on 2011-01-21

This bug report is a duplicate of: Bug #93847: Excessive CPU usage by Gnome System Monitor . Edit Remove

This bug affects 4 people

Affects		Status	Importance	Assigned to	Milestone
	gnome-system-monitor (Ubuntu)	Confirmed	Undecided	Unassigned

Bug Description

Binary package hint: gnome-system-monitor

Step to reproduce:
1. click on the System Monitor, notice that a window with CPU usage charts opens up
2. the CPU usage quickly grows. On 4 CPU machine is raises from a few percents to about 50% in about a minute and then stays on that level. The CPU usage is caused by Gnome System Monitor. It also seems to be proportional to the amount of space occupied by the chart (the part with lines), which may point to inefficiencies in plotting the chart.
3. closing down the window with chart returns the CPU consumption back to normal (1-2 percents) but minimizing the windows does not change anything.

Screenshot is attached.

Why this is a problem:
This application is supposed to provide information on CPU usage by other applications. The fact that it uses such vast amounts of CPU power itself completely skews the picture and makes the measurements useless: instead of seeing what applications are doing one can only see that the computer's CPU is overloaded by the monitoring. It is not just bad. It is worse than that. :-(

Expected behaviour:
CPU usage of the application must be negligible. The problem of drawing a few lines was never a big deal even on 20MHz machines.

Description: Ubuntu 10.10
Release: 10.10

  Installed: 2.28.1-1ubuntu1
  Candidate: 2.28.1-1ubuntu1
  Version table:
*** 2.28.1-1ubuntu1 0
        500 http://gb.archive.ubuntu.com/ubuntu/ maverick/main amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: gnome-system-monitor 2.28.1-1ubuntu1
ProcVersionSignature: Ubuntu 2.6.35-24.42-generic 2.6.35.8
Uname: Linux 2.6.35-24-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Fri Jan 21 20:22:25 2011
ExecutablePath: /usr/bin/gnome-system-monitor
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
ProcEnviron:
LANG=en_GB.utf8
SHELL=/bin/bash
SourcePackage: gnome-system-monitor

Tags:

Revision history for this message

Denys Rtveliashvili (rtvd) wrote on 2011-01-21:

screenshoot which demonstrates this problem Edit (208.9 KiB, image/png)
Dependencies.txt Edit (4.5 KiB, text/plain; charset="utf-8")
ProcMaps.txt Edit (44.6 KiB, text/plain; charset="utf-8")
ProcStatus.txt Edit (800 bytes, text/plain; charset="utf-8")
XsessionErrors.txt Edit (1.3 MiB, text/plain; charset="utf-8")

Revision history for this message

Wesley Werner (wesley-werner) wrote on 2011-03-22:

I noticed this too. When I use top in a terminal, it shows top using minimal, and gnome-system-monitor avg of 35%. In one instance, ntop used 100% CPU. I issue a 'killall ntop' and then the high CPU usage dropped away, but can't say if this was related. Will do some more checks.

Revision history for this message

Alistair Buxton (a-j-buxton) wrote on 2011-04-05:

I've seen this too, so marking confirmed. It seems to be something to do with the way the curves are drawn, possibly made worse by using compiz and nvidia.

Changed in gnome-system-monitor (Ubuntu):
status:	New → Confirmed

Revision history for this message

Dmitri Bachtin (damg) wrote on 2011-10-09:

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 93847, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.