#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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Comment(by veplaini):

 With joyride-2273 not much improvement in the midi-tests; however
 using the --sched option for csound really makes a difference: only
 1 xrun in rain.mid where there were loads.

 However --sched only works under su/sudo, as it can't lock memory
 as user OLPC. This could be worked around so that the right permissions
 are given to an 'audio' group, perhaps?

 This might not be necessary if we have a more responsive kernel. I'm
 really happy you are looking into this: previously I had the impression
 RT preemption for olpc was a no-go area. I think this is crucial for
 a laptop that will use media heavily.

 Linux is a great system for audio (probably the best), when the right
 kernel tuning is applied. AFAIK, the best kernel so far for audio is
 2.6.24[.7-rt17]. There is also a list specialised in discussing these
 issues: http://lists.linuxaudio.org/listinfo/linux-audio-tuning.

 VL

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Ticket URL: <http://dev.laptop.org/ticket/7603#comment:41>
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