Bug 1798902

Summary:	/usr/lib64/sa/sadc causes massive CPU load when logging in with USB-C dock connected.
Product:	[Fedora] Fedora	Reporter:	Christoph Pomaska <c.pomaska>
Component:	sysstat	Assignee:	Michal Sekletar <msekleta>
Status:	CLOSED EOL	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	unspecified
Version:	30	CC:	kasal, msekleta
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-05-26 18:17:33 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Christoph Pomaska 2020-02-06 09:36:46 UTC

Description of problem:
The binary /usr/lib64/sa/sadc of the sysstat package causes massive CPU load when logging in while USB-C dock is connected. It seems not to matter whether it is GDM or SDDM that is started. I use i3. I cannot reproduce the bug on Plasma as Plasma seems to get stuck aswell at some point. I assume that I will have to file another bug report on this aswell.

I seemingly cannot e.g. get kernel log output as I am unable to use "sudo" or any login process on another tty as they seem to be blocked by the high load of sadc.

I run Fedora on a Lenovo Thinkpad E490.

Version-Release number of selected component (if applicable):
11.7.3-3.fc30

How reproducible:
Always

Steps to Reproduce:
1. Boot Fedora into GDM/SDDM
2. Connect USB-C dock
3. Log in

Actual results:
/usr/lib64/sa/sadc blocks 100% CPU in htop and causes a rapidly increasing load.

Expected results:
/usr/lib64/sa/sadc not causing 100% in CPU.

Additional info:
When logging into the system with the dock not connected and connecting the dock after login the issue does not occur.

This is my first bug report on here so please suggest how I can improve it if this is necessary.

Comment 1 Christoph Pomaska 2020-02-07 09:01:09 UTC

As I was not able to find a way to edit the text above:
The reproduction steps are incorrect, sorry for that.

The correct ones are:
2. Connect USB-C dock (It doesn't matter if the dock is connected before or after the power button is pressed)
3. Boot Fedora into GDM/SDDM
3. Log in
(4. open htop in a terminal and watch it burn)

Comment 2 Ben Cotton 2020-04-30 20:28:02 UTC

This message is a reminder that Fedora 30 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora 30 on 2020-05-26.
It is Fedora's policy to close all bug reports from releases that are no longer
maintained. At that time this bug will be closed as EOL if it remains open with a
Fedora 'version' of '30'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version.

Thank you for reporting this issue and we are sorry that we were not 
able to fix it before Fedora 30 is end of life. If you would still like 
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of Fedora, you are encouraged  change the 'version' to a later Fedora 
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

Comment 3 Ben Cotton 2020-05-26 18:17:33 UTC

Fedora 30 changed to end-of-life (EOL) status on 2020-05-26. Fedora 30 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of
Fedora please feel free to reopen this bug against that version. If you
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current release. If you experience problems, please add a comment to this
bug.

Thank you for reporting this bug and we are sorry it could not be fixed.