Bug 1395825 - kswapd0 high cpu load and freezing computer
Summary: kswapd0 high cpu load and freezing computer
Keywords:
Status: CLOSED EOL
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 24
Hardware: x86_64
OS: Linux
unspecified
high
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2016-11-16 18:54 UTC by Jean-Christophe Baptiste
Modified: 2017-08-08 19:17 UTC (History)
9 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2017-08-08 19:17:05 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)
dmesg during the issue (10.49 MB, text/x-vhdl)
2016-11-16 19:45 UTC, Jean-Christophe Baptiste
no flags Details

Description Jean-Christophe Baptiste 2016-11-16 18:54:41 UTC
Description of problem:

- copy many files or big files between disks (usb to usb or internal to usb, for instance);
- after a while, kswapd0 suddenly appears on top of processes, taking 100% of one CPU core;
- computer starts slowly getting irresponsive (mouse lags, keyboard buffer, etc.) and totally freezes after a few minutes.

I can reproduce it all the time.

The issue has been reported upstream:

https://bugzilla.kernel.org/show_bug.cgi?id=65201

It is said to be fixed in kernel 4.8, but I am on Fedora 24 up-to-date with kernel 4.8.6-201.fc24.x86_64.

I have a Thinkpad T460 computer, Core i5 / Skylake architecture, 16 GB of RAM and a SSD. External drives are classic USB 3 hard drives.

Of course, my computer does not swap at all as there is plenty of free memory.

Was the patch included in the Fedora kernel?
Any idea on how to debug this?

Comment 1 Jean-Christophe Baptiste 2016-11-16 19:45:37 UTC
Created attachment 1221374 [details]
dmesg during the issue

Comment 2 Martin Gregorie 2016-12-02 13:01:43 UTC
I found this happening last night when doing a system backup using rsync as the backup program. 

It prevented the backup from completing with exactly the same the symptoms described above: 'top' clearly showed the CPU used by kswapd0 rise steadily until it held ad 100% for several seconds, followed by a total system crash.

This happened running Fedora 23 with kernel versions 4.8.10, so I rebooted into kernel 4.8.8 but it still ocurred at pretty much the same point in the backup run with the same symptoms being showed by 'top'. 

Finally, after rebooting into kernel 4.7.10 I was able to complete the backup. With this kernel I didn't notice kswapd0 CPU usage rising above 2%.

Comment 3 Justin M. Forbes 2017-04-11 14:56:03 UTC
*********** MASS BUG UPDATE **************

We apologize for the inconvenience.  There are a large number of bugs to go through and several of them have gone stale.  Due to this, we are doing a mass bug update across all of the Fedora 24 kernel bugs.

Fedora 25 has now been rebased to 4.10.9-100.fc24.  Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel.

If you have moved on to Fedora 26, and are still experiencing this issue, please change the version to Fedora 26.

If you experience different issues, please open a new bug report for those.

Comment 4 Martin Gregorie 2017-04-11 16:26:07 UTC
I haven't seen this problem since upgrading to Fedora 25.

Comment 5 Fedora End Of Life 2017-07-25 23:54:53 UTC
This message is a reminder that Fedora 24 is nearing its end of life.
Approximately 2 (two) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 24. 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 '24'.

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 24 is end of life. If you would still like
to see this bug fixed and are able to reproduce it against a later version
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 6 Fedora End Of Life 2017-08-08 19:17:05 UTC
Fedora 24 changed to end-of-life (EOL) status on 2017-08-08. Fedora 24 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
are unable to reopen this bug, please file a new report against the
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.


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