Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.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 445221

Summary: BUG in slab.c on save/restore
Product: Red Hat Enterprise Linux 5 Reporter: Aron Griffis <agriffis>
Component: kernel-xenAssignee: Xen Maintainance List <xen-maint>
Status: CLOSED DUPLICATE QA Contact: Martin Jenner <mjenner>
Severity: low Docs Contact:
Priority: low    
Version: 5.2CC: amy.griffis, aron.griffis, clalance, dchapman, jarod, ktokunag, martine.silbermann, takebe_akio, tyamamot
Target Milestone: rc   
Target Release: ---   
Hardware: ia64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-01-22 14:02:26 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:
Attachments:
Description Flags
backport of http://xenbits.xensource.com/xen-unstable.hg?rev/63263d715d43
none
ia64 slab.c corruption patch, v2 none

Description Aron Griffis 2008-05-05 15:28:28 UTC 
Description of problem:
When saving/restoring a domU, it's possible to hit the following:

BUG: sleeping function called from invalid context at /.../slab.c:2901
in_atomic():0, irqs_disabled():1

This bug was fixed upstream a year ago, see
http://xenbits.xensource.com/xen-unstable.hg?rev/63263d715d43

Version-Release number of selected component (if applicable):
kernel-2.6.18-91.el5.x86_64.rpm
(and all prior RHEL5 xen/ia64 kernels)

How reproducible:
I couldn't reproduce this on RHEL with simple save/restore testing, but upstream
says it will only happen rarely and requires a loaded domU.  Regardless, the
problem is well-understood and has been fixed upstream for a long time now, so
it would be good to see this fix preemptively in RHEL 5.x

Additional info:
I'll port the patch, test and post it to this bug
Comment 1 Aron Griffis 2008-05-06 23:01:24 UTC 
Created attachment 304696 [details]
backport of http://xenbits.xensource.com/xen-unstable.hg?rev/63263d715d43

This patch also removes a completely bogus call to xen_register_percpu_irq(). 
It's bogus because is_running_on_xen() is tested a few lines earlier and the
function returns if so.  This showed up because the patch broke the compilation
of that call, which doesn't exist in the upstream sources.  It looks like an
error (probably mine!) in the original port to fedora/rhel.
Comment 2 Aron Griffis 2008-05-06 23:03:56 UTC 
I tested this patch on kernel-2.6.18-92.el5.ia64.rpm dom0 and domU, boot plus
save/restore cycle.  Everything checks out.

(Sorry about the typo in the comment 0; I accidentally typed x86_64 instead of ia64)
Comment 3 Chris Lalancette 2009-01-15 09:46:05 UTC 
Created attachment 329074 [details]
ia64 slab.c corruption patch, v2

In order to get this patch to apply/build on the current 5.3 kernel, I had to munge it a bit.  I think I did it right, but I'm definitely no ia64 expert, so if you could give the munged patch a quick once-over, that would be great.

Thanks,
Chris Lalancette
Comment 4 Chris Lalancette 2009-01-15 14:45:24 UTC 
I've uploaded a test kernel that contains this fix (along with several others)
to this location:

http://people.redhat.com/clalance/virttest

Could the original reporter try out the test kernels there, and report back if
it fixes the problem?

Thanks,
Chris Lalancette
Comment 5 Chris Lalancette 2009-01-22 14:02:26 UTC 
Actually, while going back through BZ's, I've found that this is basically a dup of 288511.  Closing it as such.

Chris Lalancette

*** This bug has been marked as a duplicate of bug 288511 ***