Graphs don't scroll by smoothly

[Trouilliez vincent]

Binary package hint: gnome-system-monitor

The graphs now have bezier curves and look beauuutiful :-)
Here is an idea /feature request to compliment these sexy graphs:

make them scroll smoothly, and independently from the selected sampling rate.
Increasing the sampling rate (0.25s is the fastest) isn't a solution as graphs are still jerky, and it eats the CPU.
For example I normally use a sampling rate of 1 second, which yields on an idle sytem (1.5GHz CPU) a CPU load of 8%, which is already significant. If I speed up the sampling rate to 0.25s, that's 4 times faster, I get 32% CPU load (!), which is also 4 times the previous load. So increasing the sampling rate clearly isn't a solution.

So smooth scrolling graphs, and low CPU usage would be lovely :o)

ProblemType: Bug
Architecture: i386
Date: Wed Mar 14 03:33:52 2007
DistroRelease: Ubuntu 7.04
ExecutablePath: /usr/bin/gnome-system-monitor
Package: gnome-system-monitor 2.18.0-0ubuntu1
PackageArchitecture: i386
ProcCmdline: gnome-system-monitor
ProcCwd: /home/vincent
ProcEnviron:
 SHELL=/bin/bash
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/bin/X11:/usr/games
 LANG=en_GB.UTF-8
 LANGUAGE=en_GB:en
SourcePackage: gnome-system-monitor
Uname: Linux Lotus-Esprit 2.6.20-10-generic #2 SMP Mon Mar 12 00:02:49 UTC 2007 i686 GNU/Linux

[Sebastien Bacher (seb128)]

Thanks for your bug report. This bug has been reported to the developers of the software. You can track it and make comments here: http://bugzilla.gnome.org/show_bug.cgi?id=418170

[Sebastien Bacher (seb128)]

Comment from upstream:

"Seems sensible. It could gather stats at the same samping rate, but re-draw the
graph less frequently if CPU% is to high.

What would be an acceptable CPU% usage ? You seem to say that 8% is already too
much. 5% ?"

[Trouilliez vincent (vincent-trouilliez-modulonet)]

Thanks Sebastien, I have replied to him upstream, and subscribed to the bug.
Seems like he misunderstood my suggestion, so I tried to explain again to him.

[Data (ubuntuaddress)]

After the following update:

gnome-system-monitor (2.22.1-0ubuntu2) hardy-proposed; urgency=low

  * debian/patches/90_from_svn_use_less_ressources.patch:
    - change from svn to avoid using too much xorg ressources to draw graphs
      (lp: #187383)

 -- Sebastien Bacher < <email address hidden>> Tue, 06 May 2008 19:29:24 +0200

this problem does not seem to occur to me anymore.
I do not know if it was really fixed upstream or if the above change just set the refresh-timing right my accident.

Can anyone confirm?

[Trouilliez vincent (vincent-trouilliez-modulonet)]

Yes, the patch to reduce CPU resources was not successful in my case (uses 50% CPU then slowly progresses up to 100%, over a period of on eminute or so), but a nice side effect is that the graphs now scroll smoothly, cool ! :-)

So, this bug can be closed :-)

[perfran (perfran)]

I do not agree, it is still not smooth at all for me :(

[Data (ubuntuaddress)]

perfran: What version of Ubuntu are you using? Hardy? 32bit or 64bit? what CPU architecture?
Did you change the refresh rate in the preferences of system-monitor?

[perfran (perfran)]

I use Ubuntu Hardy 32 bits (i386) with an AMD64
I tried several refresh rates from 1 to 4 and the graphs are jerky
If I set 0.25 0.50 or 0.75 it is smooth but the graph goes too fast and uses 100% CPU and that's not the purpose of a cpu activity graph to eat all cpu ressources :p
I think that even with those values (0.25 0.50 or 0.75) the graph is still jerky but the steps are close enough to appear smooth ; because the more I increase the refresh rate (I mean reducing the time) the more the steps are close. With 6s , the steps are very spaced.

[Niels Egberts (nielsegberts)]

On hardy the graphs are jerky but on Intrepid they are just fine on my laptop (dual-core)