Bug 683073 – page_referenced() sometime ignores young bits with THP

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Bug 683073 - page_referenced() sometime ignores young bits with THP

Summary:	page_referenced() sometime ignores young bits with THP

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Linux 6
Classification:	Red Hat
Component:	kernel (Show other bugs)
Sub Component:
Version:	6.1
Hardware:	Unspecified Unspecified

Priority	unspecified Severity unspecified
Target Milestone:	rc
Target Release:	---
Assigned To:	Andrea Arcangeli
QA Contact:	Caspar Zhang
Docs Contact:

URL:
Whiteboard:
Keywords:	Triaged

Depends On:
Blocks:
	Show dependency tree / graph

Reported:	2011-03-08 08:15 EST by Andrea Arcangeli
Modified:	2013-07-03 03:28 EDT (History)
CC List:	3 users (show)

See Also:
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 07:59:58 EDT
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHSA-2011:0542	normal	SHIPPED_LIVE	Important: Red Hat Enterprise Linux 6.1 kernel security, bug fix and enhancement update	2011-05-19 07:58:07 EDT

Groups: None (edit)

Description Andrea Arcangeli 2011-03-08 08:15:43 EST

Description of problem: sometime the young bits could be ignored erroneously on hugepages with page_referenced()


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


How reproducible: Not easily reproducible. It may generate some unnecessary swapping.


Steps to Reproduce:
1. allocate memory, bzero it
2. fork()
3. bzero the memory in the child to trigger cows and mlock the memory in the child
  
Actual results:

The pages in the parent shouldn't be easily swapped out.

Expected results:

The pages in the parent are more easily swapped out than expected.

Comment 2 Andrea Arcangeli 2011-03-08 08:43:32 EST

I submitted a fix that applies to both RHEL6 and RHEL6.1 kernels on rhkernel-list with Message-ID: <20110308134243.GT25641@random.random>

Comment 3 RHEL Product and Program Management 2011-03-14 09:20:43 EDT

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 10:32:15 EDT

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

Comment 10 errata-xmlrpc 2011-05-19 07:59:58 EDT

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

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