Bug 690921

Summary:	Fix compaction deadlock with SLUB and loop over tmpfs
Product:	Red Hat Enterprise Linux 6	Reporter:	Andrea Arcangeli <aarcange>
Component:	kernel	Assignee:	Andrea Arcangeli <aarcange>
Status:	CLOSED ERRATA	QA Contact:	Red Hat Kernel QE team <kernel-qe>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	6.1	CC:	bdonahue
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	kernel-2.6.32-130.el6	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-05-19 12:00:03 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:

Description Andrea Arcangeli 2011-03-25 20:06:05 UTC

Description of problem: a deadlock might happen if the kernel is configured with SLUB and loop over tmpfs is used if compaction is enabled (even if THP is off).


Version-Release number of selected component (if applicable): 6.0/6.1/master


How reproducible: not reproducible (probably impossible to reproduce with RHEL6.0 and RHEL6.1 because of SLAB being selected instead of SLUB)


Steps to Reproduce:
1. build the kernel with CONFIG_COMPACTION=y and CONFIG_SLUB=y
2. create a loop over tmpfs
3. copy data to loop device (writes to the loop device that require writeback)
  
Actual results: it must not deadlock


Expected results: it might deadlock (reproduced only once by Hugh with a modified tmpfs/shmem code, not reproducible)

Comment 1 Andrea Arcangeli 2011-03-25 20:12:18 UTC

Patch submitted to rhkernel-list with Message-ID: <20110325201201.GA29142>

Comment 4 Aristeu Rozanski 2011-04-07 14:14:54 UTC

Patch(es) available on kernel-2.6.32-130.el6

Comment 8 errata-xmlrpc 2011-05-19 12:00:03 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-2011-0542.html