Re: Linux 2.6.29

David Rees
2009-04-02T16:30:32Z

On Thu, Apr 2, 2009 at 4:05 AM, Janne Grunau <j@jannau.net> wrote:
>> Current kernels just have too much IO latency
>> with ext3 it seems.
>
> MythTV calls fsync every few seconds on ongoing recordings to prevent
> stalls due to large cache writebacks on ext3.

Personally that is also one of my MythTV pet peeves. A hack added to
MythTV to work around a crappy ext3 latency bug that also causes these
large files to get heavily fragmented. That and the fact that yo have
to patch MythTV to eliminate those forced fdatasyncs - there is no
knob to turn it off if you're running MythTV on a filesystem which
doesn't suffer from ext3's data=ordered fsync stalls.

-Dave