Re: dvd+rw-tools update [6.0, DVD-R DL]

[Bill Davidsen <davidsen@tmr.com>]

Joerg Schilling wrote:

> Bill Davidsen <davidsen@tmr.com> wrote:
>
>  
>
> > > But now I see where you like to use O_DIRECT.
> > >
> > > If you use O_DIRECT for writing, it makes sense and in the same case
> > > it makes sense to use directio(fd, DIRECTIO_ON); on Solaris.
> > >
> > >
> > >      
> > By not buffering the output of mkisofs, for example, buffer space is 
> > available for reading. This makes a small improvement on a large memory, 
> > much more as the memory is smaller and read ahead could be impacted by 
> > buffering writes.
> >
> >    
> >
> > > Although on Solaris, it only saves System CPU time and I cannot see
> > > an wall clock improvement.
> > >
> > >
> > >      
> > I haven't tested there, and I bet you have not tested in small memory (I 
> > use 160MB for test).
> >
> >    
> >
> > > Whether this makes sense with the _output_ file from star or mkisofs
> > > needs to be tested.....
> > >
> > >      
> > I had not tried with the output of star, that's an interesting suggestion.
> >    
>
> I did try it recently with creating a SchilliX ISO image (~ 20000 files
> 700 MB) and it did not help.
Did you do the test on a machine with limited memory? I may have asked 
this before, but I don't see a reply, sorry if this is a repeated 
question. I find the great benefit when memory for buffers is limited.

Thanks for testing.

--
bill davidsen <davidsen@tmr.com>
 CTO TMR Associates, Inc
 Doing interesting things with small computers since 1979