Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.

For bugs related to Red Hat Enterprise Linux 5 product line. The current stable release is 5.10. For Red Hat Enterprise Linux 6 and above, please visit Red Hat JIRA https://issues.redhat.com/secure/CreateIssue!default.jspa?pid=12332745 to report new issues.

Bug 645284

Summary:	modprobe igb max_vfs>7(Max support is 7) leads to host reboot in loop
Product:	Red Hat Enterprise Linux 5	Reporter:	juzhang <juzhang>
Component:	kernel	Assignee:	Stefan Assmann <sassmann>
Status:	CLOSED ERRATA	QA Contact:	Hangbin Liu <haliu>
Severity:	medium	Docs Contact:
Priority:	low
Version:	5.6	CC:	haliu, hjia, jarod, kzhang, michen
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-01-13 21:58:10 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	652210, 652213

Description juzhang 2010-10-21 08:40:56 UTC

Description of problem:
82576 NICs max support vf is 7,however,modprobe igb max_vfs>7  leads to host reboot in loop.I enable kdump in host,however,didn't find vmcore on host.

Version-Release number of selected component (if applicable):
#uname -r
2.6.18-227.el5

#lspci | grep 82576
03:00.0 Ethernet controller: Intel Corporation 82576 Gigabit Network Connection (rev 01)
03:00.1 Ethernet controller: Intel Corporation 82576 Gigabit Network Connection (rev 01)

#rpm -qa | grep kvm
etherboot-roms-kvm-5.4.4-13.el5
kvm-tools-83-205.el5
etherboot-zroms-kvm-5.4.4-13.el5
kvm-qemu-img-83-205.el5
kvm-debuginfo-83-205.el5
kvm-83-205.el5
kmod-kvm-83-205.el5


How reproducible:
100%

Steps to Reproduce:
1.modprobe modprobe -r igb
2.modprobe igb max_vfs=8
3.
  
Actual results:
host reboot in loop.

Expected results:
At least,can't lead to host reboot.

Additional info:
I also tested on rhel6,On rhel6,After issue command "modprobe igb max_vfs=8",host is still normal although the vfs number is still 7.

Comment 1 Stefan Assmann 2010-10-22 15:49:54 UTC

This is because of missing commit c0f2276f3601a96b29d4347c5938e9494e8e4e5d and should be fixed. Could you please verify that the following build fixes the issue
https://brewweb.devel.redhat.com/taskinfo?taskID=2846207

Thanks for reporting

Comment 2 RHEL Program Management 2010-10-22 16:09:31 UTC

This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 3 juzhang 2010-10-25 02:58:46 UTC

(In reply to comment #1)
> This is because of missing commit c0f2276f3601a96b29d4347c5938e9494e8e4e5d and
> should be fixed. Could you please verify that the following build fixes the
> issue
> https://brewweb.devel.redhat.com/taskinfo?taskID=2846207
> 
> Thanks for reporting

I downloaded kernel-2.6.18-228.el5.bug628534.x86_64.rpm  form https://brewweb.devel.redhat.com/taskinfo?taskID=2846207.
I installed kernel-2.6.18-228.el5.bug628534.x86_64.rpm and tried 5 times,pass.didn't  hit this issue again.

Comment 6 Jarod Wilson 2010-10-28 20:09:10 UTC

in kernel-2.6.18-229.el5
You can download this test kernel (or newer) from http://people.redhat.com/jwilson/el5

Detailed testing feedback is always welcomed.

Comment 11 Hangbin Liu 2010-11-30 05:15:06 UTC

can't reproduce , but on kernel 2.6.18-233.el5 , the host didn't reboot in loop or print dmesg like 

 Tx Queue             <0>
  TDH                  <0>
  TDT                  <9>
  next_to_use          <9>
  next_to_clean        <0>
buffer_info[next_to_clean]
  time_stamp           <fffe817d>
  next_to_watch        <0>
  jiffies              <fffe9390>
  desc.status          <168000>
igb 0000:01:00.0: Detected Tx Unit Hang

Codereviewed,linux-2.6-net-igb-fix-tx-hang-when-loading-igb-with-max_vfs-7.patch is applied in kernel 2.6.18-233.el5 correctly.

Comment 13 errata-xmlrpc 2011-01-13 21:58:10 UTC

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2011-0017.html