Re: [iPAQ] Getting Initimate and Famliar to play nice.

On Thu, Mar 29, 2001 at 03:53:04PM +0100, pounderd@psion.net wrote:
> >snip<
> >Some form of compression for some types of files would help too.
> >snip<
>
> I think most of the executables are already gzexe'd. Is there such a thing
> as bzexe? Is it possible to compress .glade files? xml tends to take up

I would like to state that solutions to save diskspace like gzexe are
not that useful, especially on an iPaq. Yes, they will allow you to cram
more executables on a disk.

However, in order to run the application they need to be decompressed.
The decompression is done to an allocated area of memory (malloc or
anonymous mmap), this memory is not shared between running processes and
cannot be 'paged', i.e. under memory pressure the executable code has to
be written to swapspace.

So this solution will gobble up memory for applications of which
multiple instances are running, such as xterms or perhaps the python
interpreter. It is also not very good for larger applications, being
able to simply discard unused code pages of the X-server and reload them
whenever they are needed is something you'd pretty much want to rely on
with a small memory machine that doesn't provide swapspace.

So what is left over are the small files. For these, efficient
compression is harder to achieve, and ext2 doesn't pack multiple files
in a single (1K or even 4K) block will pretty much remove any
usefullness in this area.

Compressing data files does sometimes pay off, it is possible to use a
LD_PRELOAD trick to allow unmodified application to read gzip compressed
datafiles.
    http://www.delorie.com/gnu/docs/zlibc/zlibc.3.html

Another really useful set of tools to save diskspace is perforate, which
consists of
    zum recreate holes (remove 0-filled blocks) in files.
    finddup/nodup find/relink non-hardlinked duplicates of files.
    findstrip find unstripped executables.

Perforate is part of the Debian distribution. According to the package,
the sources were obtained from:

    ftp://gd.cs.CSUFresno.EDU:/pub/sun4bin/src

> libraries in different places - which would be silly.) Even when it comes
> to hard-linking files to the Familiar files in the flash could cause

It is not possible to create hardlinks between different filesystems.

Jan
Received on Thu Mar 29 07:56:46 2001