Bug 1429951 – [rt] fs: dcache: Use cpu_chill() in trylock loops

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Bug 1429951 - [rt] fs: dcache: Use cpu_chill() in trylock loops

Summary:	[rt] fs: dcache: Use cpu_chill() in trylock loops

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Linux 7
Classification:	Red Hat
Component:	kernel-rt (Show other bugs)
Sub Component:
Version:	7.4
Hardware:	x86_64 Linux

Priority	medium Severity medium
Target Milestone:	rc
Target Release:	---
Assigned To:	Clark Williams
QA Contact:	Jiri Kastner
Docs Contact:

URL:
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Depends On:
Blocks:	1353018 1410158
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Reported:	2017-03-07 10:01 EST by Clark Williams
Modified:	2018-02-08 12:36 EST (History)
CC List:	3 users (show)

See Also:
Fixed In Version:
Doc Type:	If docs needed, set a value
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Story Points:	---
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Environment:
Last Closed:	2017-08-01 15:02:59 EDT
Type:	Bug
Regression:	---
Mount Type:	---
Documentation:	---
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Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
fs: dcache: Use cpu_chill() in trylock loops (5.18 KB, patch) 2017-03-07 10:01 EST, Clark Williams	no flags	Details \| Diff
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHSA-2017:2077	normal	SHIPPED_LIVE	Important: kernel-rt security, bug fix, and enhancement update	2017-08-01 14:13:37 EDT

Groups: None (edit)

Description Clark Williams 2017-03-07 10:01:46 EST

Created attachment 1260846 [details]
fs: dcache: Use cpu_chill() in trylock loops

Retry loops on RT might loop forever when the modifying side was
preempted. Use cpu_chill() instead of cpu_relax() to let the system
make progress.
    
Note: this is a partial port for RHEL, only touching the changes in
fs/dcache.c. The other hunks of this patch (the s/cpu_relax/cpu_chill/)
were applied earlier.

Comment 2 Clark Williams 2017-03-07 10:03:54 EST

tested with scratch build:

https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=12698074

Comment 8 errata-xmlrpc 2017-08-01 15:02:59 EDT

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2017:2077

Comment 9 errata-xmlrpc 2017-08-01 20:25:36 EDT

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2017:2077

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