Top showing 9999% CPU usage

Bug #531310 reported by tdn
48
This bug affects 10 people
Affects Status Importance Assigned to Milestone
procps (Ubuntu)
Confirmed
Undecided
Unassigned

Bug Description

Binary package hint: procps

In the attached screenshot, 'top' is showing 9999% CPU usage for the firefox process. This is not possible.

ProblemType: Bug
Architecture: i386
Date: Wed Mar 3 13:28:18 2010
DistroRelease: Ubuntu 9.10
NonfreeKernelModules: nvidia
Package: procps 1:3.2.8-1ubuntu3
ProcEnviron:
 LANGUAGE=
 PATH=(custom, user)
 LANG=en_DK.UTF-8
 SHELL=/bin/zsh
ProcVersionSignature: Ubuntu 2.6.31-19.56-generic
SourcePackage: procps
Uname: Linux 2.6.31-19-generic i686
XsessionErrors: (polkit-gnome-authentication-agent-1:2629): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed

Revision history for this message
tdn (spam-thomasdamgaard) wrote :
Revision history for this message
Robert C. Sheets (rcsheets) wrote :

I also saw this, but for the eucalyptus-cloud process, shortly after startup.

Revision history for this message
Søren Holm (sgh) wrote :

I allso see this sometimes. I'm guessing it is some kind of division by zero or such in top. It only applies to one top-"sample".

Revision history for this message
Tomasz (Tomek) Muras (zabuch) wrote :

Like the note above: I've seen it for few different processes but always for the top entry in "top". I'm running on 64 bit Ubuntu Desktop 10.04.

Revision history for this message
Tomasz (Tomek) Muras (zabuch) wrote :
Revision history for this message
Max Barry (max-maxbarry) wrote :

Seen frequently in 64-bit Ubuntu Server 10.04, usually in an apache2 process.

Related to this? http://kerneltrap.org/mailarchive/linux-kernel/2007/10/3/328379/thread

Revision history for this message
Max Barry (max-maxbarry) wrote :

Just in case it matters, screenshot of it happening with a defunct process too.

Revision history for this message
James (james-ellis-gmail) wrote :

Started seeing this after I started using Thunderbird as an email client.

The process is "fuser" and top shows 9999% CPU. General CPU usage rises while 9999% is in use to about 50%.

32bit Kubuntu 11.10

Processor: Intel(R) Core(TM)2 Duo CPU T9300 @ 2.50GHz

Revision history for this message
James (james-ellis-gmail) wrote :

Cause of fuser going bonkers (for me) is this bug:

https://bugs.launchpad.net/ubuntu/+source/php5/+bug/876387

That doesn't relate to the erroneous 9999% reporting though.

Revision history for this message
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in procps (Ubuntu):
status: New → Confirmed
Revision history for this message
Asterix Gaulês (asterixgaules) wrote :

It seems that the bug is in the CPU time calculation for the process. Some samples display a smaller time than the previous sample, thus resulting in negative CPU % for that period, which explains the overflow value that appears (9999.0)

To post a comment you must log in.
This report contains Public information  
Everyone can see this information.

Duplicates of this bug

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.