Re: Linux 2.6.29

From: David Rees
Date: Thu Apr 02 2009 - 12:30:33 EST


On Thu, Apr 2, 2009 at 4:05 AM, Janne Grunau <j@xxxxxxxxxx> 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/