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Bug 1108292

Summary: alsaloop uses 100% CPU when playing HTML5 video in Firefox
Product: Red Hat Enterprise Linux 6 Reporter: Martin <mholec>
Component: alsa-utilsAssignee: Jaroslav Kysela <jkysela>
Status: CLOSED ERRATA QA Contact: Ken Benoit <kbenoit>
Severity: high Docs Contact: Mark Flitter <mflitter>
Priority: unspecified    
Version: 6.6CC: jkoten, jkysela, jshortt, kbenoit, kernel-qe-hw, tlavigne, tpelka
Target Milestone: rcKeywords: Reopened
Target Release: 6.9   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Resolution for the alsaloop daemon consuming 100% CPU Under some configurations, the alsaloop daemon could improperly use all CPU time for one or more CPUs. This fix resolves the issue by the addition of new error checking code.
Story Points: ---
Clone Of: Environment:
Last Closed: 2017-03-21 11:06:29 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: 1245602    
Bug Blocks: 1269638, 1346447    

Description Martin 2014-06-11 16:27:54 UTC
Description of problem:
alsaloop uses 100% CPU when playing HTML5 video in Firefox.

Version-Release number of selected component (if applicable):
alsa-utils-1.0.22-5.el6.x86_64
alsa-lib-1.0.22-3.el6.x86_64
kernel-2.6.32-474.el6.x86_64

How reproducible:
always

Steps to Reproduce:
Execute test case: https://tcms.engineering.redhat.com/case/165694/?from_plan=6110
play https://www.youtube.com/watch?v=C2ODfuMMyss

Actual results:
alsaloop starts using 100% CPU after a while

Comment 11 Ken Benoit 2016-03-31 13:57:01 UTC
Tested on a few different systems using RHEL-6.8-20160330.0. After successfully setting up alsaloop using alsa-delay I started up top in order to monitor CPU usage and then loaded up an HTML5 video on Youtube. Within anywhere from 5 seconds to 90 seconds I saw alsaloop hit 100% CPU usage. Reproduced after multiple reboots of each machine as well.

Comment 17 Jaroslav Kysela 2016-10-18 12:02:30 UTC
Fix:

http://git.alsa-project.org/?p=alsa-utils.git;a=commitdiff;
h=e61f35ba4dd1bb0802320d25ecbc8a31ed85caea

Comment 19 Ken Benoit 2016-11-30 18:13:00 UTC
Tested using RHEL-6.9-20161128.n.0 (i386 and x86_64 Workstation) on a system and tried the test from the summary. I have not seen the CPU usage for alsaloop go above 6% during any of the tests whereas when testing against 6.8 I would see the CPU usage hit 100% within a few minutes. Marking as verified.

Comment 21 errata-xmlrpc 2017-03-21 11:06:29 UTC
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://rhn.redhat.com/errata/RHBA-2017-0714.html