Bug 444765

Summary: virtio_net driver causing hang at shutdown
Product: [Fedora] Fedora Reporter: Mark McLoughlin <markmc>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED CURRENTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: high    
Version: 9CC: berrange, chrisw, katzj
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: 2.6.25.4-30.fc9 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2008-06-06 07:44:28 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description Flags
0001-virtio_net-free-transmit-skbs-in-a-timer.patch none

Description Mark McLoughlin 2008-04-30 14:48:13 UTC
Running KVM guests with a virtio nic, I'm seeing a hang at shutdown at
"iptables: Unloading modules:"

Turns out nf_conntrack is blocking because virtio_net has left a TX skb dangling.

See:

  http://lkml.org/lkml/2008/4/30/207

Adding to F9Blocker because shutdown hangs suck and the fix seems fairly safe.

Comment 1 Mark McLoughlin 2008-04-30 14:48:13 UTC
Created attachment 304236 [details]
0001-virtio_net-free-transmit-skbs-in-a-timer.patch

Comment 2 Bug Zapper 2008-05-14 10:26:03 UTC
Changing version to '9' as part of upcoming Fedora 9 GA.
More information and reason for this action is here:
http://fedoraproject.org/wiki/BugZappers/HouseKeeping

Comment 3 Chuck Ebbert 2008-05-17 02:07:41 UTC
Did we get a better fix for this? Upstream didn't really like the proposed one...

Comment 4 Mark McLoughlin 2008-05-19 09:01:59 UTC
(In reply to comment #3)
> Upstream didn't really like the proposed one...

No, upstream wants to add a *host* feature to throttle tx notification
interrupts and have the guest detect when that feature is available. When it
isn't available, the guest will need to poll for tx completion in a timer.

So, upstream is going to merge my patch and later add the throttling feature to
the host and the guest-side code to take advantage of it:

  http://lkml.org/lkml/2008/5/19/26

Comment 5 Chuck Ebbert 2008-05-20 08:35:06 UTC
Patch in 2.6.25.4-29

Comment 6 Fedora Update System 2008-05-22 15:33:03 UTC
kernel-2.6.25.4-30.fc9 has been submitted as an update for Fedora 9

Comment 7 Fedora Update System 2008-05-29 02:51:03 UTC
kernel-2.6.25.4-30.fc9 has been pushed to the Fedora 9 testing repository.  If problems still persist, please make note of it in this bug report.
 If you want to test the update, you can install it with 
 su -c 'yum --enablerepo=updates-testing update kernel'.  You can provide feedback for this update here: http://admin.fedoraproject.org/updates/F9/FEDORA-2008-4630

Comment 8 Fedora Update System 2008-06-06 07:44:08 UTC
kernel-2.6.25.4-30.fc9 has been pushed to the Fedora 9 stable repository.  If problems still persist, please make note of it in this bug report.