Bug 687918

Summary:	thp+memcg-numa: fix BUG at include/linux/mm.h:370!
Product:	Red Hat Enterprise Linux 6	Reporter:	Andrea Arcangeli <aarcange>
Component:	kernel	Assignee:	Andrea Arcangeli <aarcange>
Status:	CLOSED ERRATA	QA Contact:	Caspar Zhang <czhang>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	6.1	CC:	czhang, qcai, tburke
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	kernel-2.6.32-128.el6	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-05-19 12:00:00 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 2011-03-15 17:48:48 UTC

Description of problem: with CONFIG_NUMA=n and memcg and transparent hugepage enabled, there could be a double free later leading to VM_BUG_ON in get_page().

How reproducible: only reproducible on x86-64 with CONFIG_NUMA=n but all x86-64 kernels with transparent hugepage support enabled should have CONFIG_NUMA=y. So it shouldn't be reproducible.


Steps to Reproduce:
1. build RHEL6 with CONFIG_NUMA=n, CONFIG_TRANSPARENT_HUGEPAGE=y
2. enable memcg
3. exaust the memcg limit from regular allocations and swapout
4. swapin
5. after swapin khugepaged will fail the compaction with memcg exausted -> bug
  
Actual results:

double free and oops

Expected results:

khugepaged should fail silently without double free or oopses


Additional info: It shouldn't be reproducible in RHEL6/6.1 because all x86-64 kernels have CONFIG_NUMA=y.

Comment 2 Andrea Arcangeli 2011-03-15 17:55:03 UTC

Fix posted to rhkernel-list with Message-ID: <20110315175252.GQ10696>.

Comment 3 RHEL Program Management 2011-03-16 10:09:53 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 4 Aristeu Rozanski 2011-03-30 14:33:10 UTC

Patch(es) available on kernel-2.6.32-128.el6

Comment 9 errata-xmlrpc 2011-05-19 12:00:00 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