Bug 1241815 - "powersave" profile makes network unstable
Summary: "powersave" profile makes network unstable
Status: CLOSED EOL
Alias: None
Product: Fedora
Classification: Fedora
Component: tuned
Version: 22
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Jaroslav Škarvada
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Keywords:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2015-07-10 07:35 UTC by Tomasz Torcz
Modified: 2016-07-19 15:17 UTC (History)
4 users (show)

(edit)
Clone Of:
(edit)
Last Closed: 2016-07-19 15:17:05 UTC


Attachments (Terms of Use)


External Trackers
Tracker ID Priority Status Summary Last Updated
Red Hat Bugzilla 1151865 None None None Never

Internal Trackers: 1151865

Description Tomasz Torcz 2015-07-10 07:35:03 UTC
Description of problem:
After enabling "powersave" profile, network interface very often loses link for 1.5-2.5 seconds. On profile "balance" network is stable.

[1713411.927023] r8169 0000:04:00.0 enp4s0: link down
[1713411.927090] lan: port 1(enp4s0) entered disabled state
[1713411.940953] r8169 0000:05:00.0 enp5s0: link down 
[1713413.438907] r8169 0000:05:00.0 enp5s0: link up
[1713414.297172] r8169 0000:04:00.0 enp4s0: link up


Version-Release number of selected component (if applicable):
tuned-2.4.1-5.fc22.noarch
kernel-4.0.5-300.fc22.x86_64


Steps to Reproduce:
1. tunedadm profile powersave
2. observe link flapping
3. tuneadm profile balanced
4. link does not flap


Additional info:
I did not found anything obvious wrt network configuration in "powersave" profile definition.

I previously reported the bug against kernel:
https://bugzilla.redhat.com/show_bug.cgi?id=1151865                                                                                                                                                                                                                               
Just now I found tuned profile link.

Comment 1 Jaroslav Škarvada 2015-07-10 09:35:55 UTC
Hi, this is probably caused by dynamic tuning switching network interface speed according to its utilization. You can switch it globally off by setting:

dynamic_tuning = 0

in /etc/tuned/tuned-main.conf. AFAIK it can save few mW of energy, but it can also cause trouble with some network adapters. In next tuned release (hopefully 2.6) there is planned more fine grained configuration option which should allow switching it off only for network plugin.

Comment 2 Tomasz Torcz 2015-07-10 15:20:45 UTC
Bingo! After disabling dynamic tuning link no longer flaps (no matter which profile is selected). Thank you.

Comment 3 Fedora End Of Life 2016-07-19 15:17:05 UTC
Fedora 22 changed to end-of-life (EOL) status on 2016-07-19. Fedora 22 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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