Bug 3300

Summary:	High cpu load appears when plugging in a USB stick
Product:	Mageia	Reporter:	Philippe Leblanc <philippel>
Component:	RPM Packages	Assignee:	Mageia Bug Squad <bugsquad>
Status:	RESOLVED WONTFIX	QA Contact:
Severity:	major
Priority:	Normal	CC:	arnaud.patard, cjw, dmorganec, fundawang, mageia, misc, thierry.vignaud, tmb
Version:	1
Target Milestone:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Source RPM:	dbus-1.4.1-3.mga1, udev-166-5.mga1	CVE:
Status comment:

Description Philippe Leblanc 2011-11-08 23:57:31 CET

Description of problem:
When I plug in my USB stick, my system begins to exhibit unusually high cpu load (>80% on dual core system) making the system very slow and unresponsive. The super high load persists even after unmounting the USB stick. I'm not sure if the problem is caused by dbus, but I was able to kill the dbus-daemon process to stop the high cpu load as a workaround. However, it seems like many processes are involved in mounting external storage devices so I don't know for certain it's dbus.

Version-Release number of selected component (if applicable):


How reproducible:
It usually does it every time I plug it in on a fresh start. However, I haven't figured out how to mount the USB stick after killing dbus-daemon thus so far I can only get the bug to manifest once before having to reboot.

Steps to Reproduce:
1. Insert USB stick.
2. Wait a minute or two.
3. Run top or activity monitor and notice high cpu load.

Comment 1 Philippe Leblanc 2011-11-09 01:53:51 CET

Upon further inspection, it looks like the actual process that's showing very high load is /sbin/udevd -d.

 PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
---------------------------------------------------------------------------
 116 root      16  -4  284m 275m  452 R   89  8.4  48:21.76 /sbin/udevd -d 

In this light, I will add udev as a possible culprit.

Source RPM: dbus-1.4.1-3.mga1 => dbus-1.4.1-3.mga1, udev-166-5.mga1

Comment 2 Philippe Leblanc 2011-11-09 22:00:54 CET

New information. I discovered that the high cpu load eventually subsides after removing the USB stick. I didn't clock it exactly, but the cpu load from udevd slowly decreased over the course of 2 or 3 hours until the system was back to normal.

Manuel Hiebel 2011-11-21 19:00:51 CET

CC: (none) => arnaud.patard, cjw, dmorganec, fundawang, mageia, misc, thierry.vignaud, tmb

Comment 3 Philippe Leblanc 2011-11-23 19:22:42 CET

I did some research and discovered this might be due to the specific USB stick I was using. I use a Sandisk Cruzer which comes with U3 software. The U3 software acts like a virtual CD drive and is mounted separately from the storage partition on the stick. This partition configuration appears to cause problems with udevd hence the high cpu load. I reformated my usb stick and removed the U3 system and now the problem is gone.

I don't know what to do about the bug though. Is it considered resolved?

Comment 4 Thierry Vignaud 2011-11-23 19:25:18 CET

I would say so

Status: NEW => RESOLVED
Resolution: (none) => WONTFIX