Bug 1348620

Summary:	glibc: malloc may fall back to calling mmap prematurely if arenas are contended
Product:	[Fedora] Fedora	Reporter:	Florian Weimer <fweimer>
Component:	glibc	Assignee:	Florian Weimer <fweimer>
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	26	CC:	arjun, ashankar, codonell, dj, fweimer, jakub, law, mcermak, mfabian, mnewsome, pfrankli, qe-baseos-tools-bugs, siddhesh, spoyarek
Target Milestone:	---	Keywords:	Patch
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	glibc-2.22-18.fc23, glibc-2.23.1-10.fc24, glibc-2.23.90-24.fc25	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:	1255822	Environment:
Last Closed:	2017-10-11 12:13:45 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:
Bug Blocks:	1255822

Description Florian Weimer 2016-06-21 15:18:31 UTC

+++ This bug was initially created as a clone of Bug #1255822 +++

Description of problem:
Due to the robust malloc changes, malloc functions may end up calling mmap prematurely if all arenas are contended but not corrupt.  This is not a serious issue in the general case and its performance impact is also questionable because it is not clear if the contention is more expensive in terms of time than a system call.  It is however expensive resource-wise if the block requests are significantly smaller than page size because that will create a lot of external holes.

See also: bug 1246713 for rhel-6, where this problem is one of two problems that the bug report mentioned.

Comment 1 Jan Kurik 2016-07-26 04:09:04 UTC

This bug appears to have been reported against 'rawhide' during the Fedora 25 development cycle.
Changing version to '25'.

Comment 2 Fedora Update System 2016-08-18 15:16:46 UTC

glibc-2.23.1-10.fc24 has been submitted as an update to Fedora 24. https://bodhi.fedoraproject.org/updates/FEDORA-2016-5f050a0a6d

Comment 3 Fedora Update System 2016-08-18 17:32:58 UTC

glibc-2.22-18.fc23 has been submitted as an update to Fedora 23. https://bodhi.fedoraproject.org/updates/FEDORA-2016-87dde780b8

Comment 4 Fedora Update System 2016-08-19 00:21:59 UTC

glibc-2.22-18.fc23 has been pushed to the Fedora 23 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2016-87dde780b8

Comment 5 Fedora Update System 2016-08-19 00:58:27 UTC

glibc-2.23.1-10.fc24 has been pushed to the Fedora 24 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2016-5f050a0a6d

Comment 6 Fedora Update System 2016-08-19 19:52:27 UTC

glibc-2.23.1-10.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.

Comment 7 Fedora Update System 2016-09-02 23:20:53 UTC

glibc-2.22-18.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

Comment 8 Fedora End Of Life 2017-02-28 09:59:29 UTC

This bug appears to have been reported against 'rawhide' during the Fedora 26 development cycle.
Changing version to '26'.