[mythtv-commits] Ticket #9150: RingBuffer/ThreadedFileWriter + fadvise

[MythTV]

#9150: RingBuffer/ThreadedFileWriter + fadvise
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 Reporter:  danielk           |           Owner:  danielk   
     Type:  enhancement       |          Status:  accepted  
 Priority:  minor             |       Milestone:  0.25      
Component:  MythTV - General  |         Version:  Trunk Head
 Severity:  medium            |      Resolution:            
 Keywords:                    |   Ticket locked:  0         
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Comment (by danielk):

 The 9150-ioprio-v1.patch can be applied with or without 9150-v2.patch. The
 problem it is intended to solve is a stutter you can get while
 mythcommflag is consuming copious amounts of disk I/O and you are using
 the CFQ I/O scheduler. This doesn't happen if you use a more MythTV
 appropriate disk I/O scheduler like deadline, but since CFQ is the default
 this is worth addressing. With 9150-v2 applied this doesn't happen for me
 with local disks or with myth streaming from a locally visible disk, but
 it still happens with NFS shares.

 The 9150-ioprio patch is untested, but I've tested the ioprio concept via
 ionice and it works. I just can't test it right now without affecting WAF.
 (I'm also setting the process priority and ionice might be setting the
 process group priority, I didn't look at their code. Or I may have made a
 typo or something like that.)

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Ticket URL: <http://svn.mythtv.org/trac/ticket/9150#comment:2>
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