[mythtv] fix for IOBOUND - blocking in ThreadedFileWriter::Write

[Mudit Wahal]

I changed the scheduler to cfq, and changed back to default
libmythtv0.18 (2MB buffer).
I'm getting 
2005-07-07 17:22:13.294 IOBOUND - blocking in ThreadedFileWriter::Write()
2005-07-07 17:22:15.468 IOBOUND - blocking in ThreadedFileWriter::Write()
2005-07-07 17:22:19.489 IOBOUND - blocking in ThreadedFileWriter::Write()
2005-07-07 17:22:23.995 IOBOUND - blocking in ThreadedFileWriter::Write()
2005-07-07 17:22:29.346 IOBOUND - blocking in ThreadedFileWriter::Write()

So, the cfq scheduler doesn't help at all. I'll revert back to 16MB
buffer library. May be if i find time in the weekend, I'll change my
/myth file system to jfs and try it out again with 2mb library.

Thanks

Mudit

On 7/7/05, Torbjörn Jansson <torbjorn.jansson at mbox200.swipnet.se> wrote:
> mythtv-dev-bounces at mythtv.org <> wrote:
> > Hi,
> >
> > I'm running myth 0.18 release version on a 2.6.12.1 kernel. My card is
> > HD3000 HDTV tuner card. I've one 180GB hard drive in my setup,
> > standard knoppix myth partition. /, /root, /cache and /myth , are all
> > ext 3.
> >
> > Whenever the tuner is recording a program, and I try to copy a large
> > file, I get the following error message in the backend logs.
> >
> > 2005-07-06 16:07:00.217 IOBOUND - blocking in
> > ThreadedFileWriter::Write()
> > 2005-07-06 16:07:05.419 IOBOUND - blocking in
> > ThreadedFileWriter::Write()
> > 2005-07-06 16:07:09.360 IOBOUND - blocking in
> > ThreadedFileWriter::Write()
> > 2005-07-06 16:07:17.400 IOBOUND - blocking in
> > ThreadedFileWriter::Write()
> > 2005-07-06 16:07:26.623 IOBOUND - blocking in
> > ThreadedFileWriter::Write()
> > 2005-07-06 16:07:31.437 IOBOUND - blocking in
> > ThreadedFileWriter::Write()
> >
> > If I stop the copy, the message will also stop.
> >
> 
> One thing you may want to try is to change the io scheduler to cfq (
> elevator=cfq argument to kernel at boot )
> That should allow each program to get equal access to the disk so one one is
> starved
> 
> I think cfq is the default for fedora.
> 
> These 2 links may be of intrest:
> http://lwn.net/Articles/22429/
> http://www.redhat.com/magazine/008jun05/features/schedulers/
> 
> 
>