Bug 1400305

Summary: RT kernel panics with dm-multipath enabled [mrg]
Product: Red Hat Enterprise MRG Reporter: Beth Uptagrafft <bhu>
Component: realtime-kernelAssignee: Clark Williams <williams>
Status: CLOSED ERRATA QA Contact: Lin Li <lilin>
Severity: high Docs Contact:
Priority: unspecified    
Version: 2.5CC: agk, bhu, bmarzins, lgoncalv, lilin, mpoledni, msnitzer, nsoffer, williams, xni, yizhan
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Cause: An upstream RT commit (fef016306919048a) was missed that made the DM system RT aware. The worker function dm_old_request_fn() was checking to ensure that irqs were disabled, but RT changes how preemption works with spinlocks so the check is invalid on RT. Consequence: Kernel panics on boot when dm-multipath module is loaded. Fix: Apply upstream RT commit fef016306919048a. This commit changes a BUG_ON macro to a BUG_ON_NONRT, which on RT becomes a noop. Result: No panic in when booting a kernel with dm-multipath module enabled.
 Story Points: ---
Clone Of: 1389215 Environment:
Last Closed: 2017-01-17 18:03:00 UTC Type: Bug
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: 1389215    
Bug Blocks:    

Comment 6 errata-xmlrpc 2017-01-17 18:03:00 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2017-0113.html