GNOME Bugzilla – Bug 572082
System monitor applet - innacurate RAM utilization graph
Last modified: 2012-11-10 00:09:05 UTC
Please describe the problem: Posted by: schtarbux on 2008-05-06 Binary package hint: gnome-system-monitor I've got two vmware sessions running (one at 1.1G ram and one at .5G), Gnome with compiz, Firefox etc.... The processes tab reports these using (what sounds like) the right amount of ram but the graph sits right at 600meg. ProblemType: Bug Architecture: amd64 Date: Tue May 6 14:36:21 2008 DistroRelease: Ubuntu 8.04 ExecutablePath: /usr/bin/gnome-system-monitor NonfreeKernelModules: nvidia ath_hal Package: gnome-system-monitor 2.22.0-1ubuntu3 PackageArchitecture: amd64 ProcEnviron: LANG=en_US.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games SHELL=/bin/bash SourcePackage: gnome-system-monitor Uname: Linux 2.6.24-16-generic x86_64 Posted by: Nick Verbeck on 2008-05-12 I am also seeing gnome-system-monitor showing inacurate Memory usage all around. The Line Graph shows less then 50% usage and the Pie Graph shows 33% usage but when I view memory usage in TOP I get a very diffrent result. A much lower result of free memory. This is a clean install on a base system(Not a VM) Posted by: Razeor on 2008-11-09 I am seeing the same issue. I have 2 x vm's running. One which is allocated 768mb ram and the other 512. I have attached a screenshot of the issue. Both VM's are running at the time of capture. I don't know if its possible (or even the right place to request this), but if the system monitor could detect vm ram usage and display it on the graphs in a different colour (or colours per vm) that would be awesome! For example: the memory pie graph could be made up of multiple different coloured sections dependent on host and guest vm ram usage. If you need more info or someone to beta test any changes, let me know. A picture of the issue can be seen here: http://launchpadlibrarian.net/19522224/ramissue.png Steps to reproduce: 1. Run Multiple VMware images on a Ubuntu host. 2. Compare the top memory information with the System-Monitor information. 3. Actual results: Please see picture: http://launchpadlibrarian.net/19522224/ramissue.png Expected results: It is expected that the memory utilization matches actual usage. Does this happen every time? yes Other information:
I confirm this bug on my machine. I'm just running normal stuff like browsers, etc. Screenshot: http://www.nilbus.com/pub/gnome.bugzilla.org-572082.png top reports 1789796k usage gnome-system-monitor reports 894.3Mib usage I also included output from /proc/meminfo in the screenshot.
You're misreading what system-monitor tells you. It's user memory. Nobody cares about physical memory used because on modern unix systems, it's almost always 100%. And even on vista. So what matters is "MemFree + Buffers + Cached", which is what system-monitor calls "User memory" since it's memory used by userspace.
>> Nobody cares about physical memory used because on modern unix systems, it's almost always 100%. Is that true? On newer machines with enough ram, it's not usually the case. I do know that when top reports physical memory is 100% used, it starts using swap, which is when things start getting slow. This is what I'm trying to avoid
Totally. As you can see, your example perfectly fits: 2G of RAM, of which 1.2 is cache. Your kernel swaps because it finds unused/leaked pages and thinks your ram could be better used. If you're not happy with it, you can touch your vm swappiness. I have access to a wide range of computers, from workstation with 16GB of RAM to a 128-way SMP with 256GB of RAM. And soon or later, their top reports 100% memory usage because the kernel makes cache of it. On a 16GB workstation, it usually takes less than a day for the kernel to fill all the available memory.
[Adding missing "QA Contact" entry so system monitor bug report changes can still be watched via the "Users to watch" list on https://bugzilla.gnome.org/userprefs.cgi?tab=email when the assignee is changed to an individual.]
I still see this, however I'm not sure what would be the proper solution to fix this, based on Benoît Dejean's comments. I'm not sure if we should show kernel memory, but maybe we could add an option in preferences for that, defaulting to OFF, and if a user wants to see the same numbers as top shows, he should explicitly set this preference. What do you think?
Closing this bug report as no further information has been provided. Please feel free to reopen this bug if you can provide the information asked for. Thanks!