Re: [PATCH] s390: Hypervisor File System

From: Michael Holzheu
Date: Wed May 03 2006 - 09:18:20 EST


Hi Jörn,

Jörn Engel <joern@xxxxxxxxxxxxxxxxxxxx> wrote on 05/03/2006 03:00:43 PM:
> On Wed, 3 May 2006 14:51:53 +0200, Michael Holzheu wrote:
> > Jörn Engel <joern@xxxxxxxxxxxxxxxxxxxx> wrote on 05/03/2006 02:33:39
PM:
> >
> > > Applications will depend on some arcane detail of your format. They
> > > will depend on exactly five spaces in "foo bar". It does not
even
> > > matter if you documented "any amount of whitespace". The application
> > > knows that it was five spaces and doesn't care. And once you change
> > > it, the blame will be on you, because you broke existing userspace.
> >
> > Again, logically there is no difference between the two solutions. It
does
> > not matter, if you have one file with:
> >
> > <cpu>
> > <0>
> > <onlinetime = 4711>
> > <\0>
> > <\cpu>
>
> Userspace can make your life hell by depending on indentation via 4
> spaces. The problem is that you don't necessarily know that it does
> until you managed to change indentation.

Of course! But the convention must be, that If userspace wants to
access the data, it has to use our standard linux
parser. If it accesses the data directly, this is broken.
This ensures, that whitespaces do not matter at all! And as
I said before, if you use the parser, you don't have any
difference compared to the filesystem solution from a logical
perspective.

Michael

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