#7603 HIGH 8.2.0 (: 2.6.25 audio performance regression

[Zarro Boogs per Child]

#7603: 2.6.25 audio performance regression
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   Reporter:  dsd       |       Owner:  dilinger                            
       Type:  defect    |      Status:  new                                 
   Priority:  high      |   Milestone:  8.2.0 (was Update.2)                
  Component:  kernel    |     Version:  not specified                       
 Resolution:            |    Keywords:  joyride-2181:- 8.2.0:? blocks?:8.2.0
Next_action:  diagnose  |    Verified:  0                                   
  Blockedby:            |    Blocking:                                      
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Changes (by dsaxena):

  * next_action:  never set => diagnose


Comment:

 I did some Googling around of "ALSA underrun scheduler" and found
 https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/190754 and
 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/188226. By enabling
 group scheduling and forcing all applications to be in one group by
 disabling per-UID scheduling groups, I can run TamTamMini for 10+ minutes
 with an average of < 1 underrun per second.

 I also think that we should put the call to SCHED_RR back into Clooper. It
 looks to me like this got dropped at some point and my (rudimentary so
 far) testing shows further improvement with
 this scheduling policy enabled (I've gone 10 minutes with zero underruns
 at one point)

 Patches will follow.

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Ticket URL: <http://dev.laptop.org/ticket/7603#comment:31>
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