Bug 1400144

Summary:	glibc: Performance penalty due to block size-based buffering in stdio
Product:	[Fedora] Fedora	Reporter:	Florian Weimer <fweimer>
Component:	glibc	Assignee:	glibc team <glibc-bugzilla>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	26	CC:	arjun.is, codonell, dj, fweimer, jakub, law, mfabian, pfrankli, siddhesh
Target Milestone:	---	Keywords:	Patch
Target Release:	---
Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	If docs needed, set a value
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Clone Of:	988869	Environment:
Last Closed:	2017-10-09 11:48:23 UTC	Type:	Bug
Regression:	---	Mount Type:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	988869

Description Florian Weimer 2016-11-30 14:29:12 UTC

For some network file systems, the kernel returns block size values of several megabytes.  The stdio streams auto-tuning in glibc currently allocates matching buffer sizes.  This causes significant performance problems if the applications uses stdio streams for non-sequential file access.

We should backport the upstream patch to fix this.

Comment 1 Fedora End Of Life 2017-02-28 10:41:50 UTC

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

Comment 2 Florian Weimer 2017-10-09 11:48:23 UTC

This is included in glibc 2.25 (Fedora 26) and glibc 2.26 (Fedora 27).