Re: [RFC] mapping parts of shared memory

[Christoph Rohland <hans-christoph.rohland@sap.com>]

viro@math.psu.edu (Alexander Viro) writes:

> On Thu, 2 Dec 1999, Bruno Haible wrote:
> 
> > 5) Use the proc filesystem. Implement a file /proc/ipc/shm/42 as being
> >    equivalent to the shared memory segment with id 42.
> >    File type: regular file
> >    File size: the shm segment's size
> >    File contents (for use by read, write, mmap): the shm segment's data
> >    File owner/group: the shm segment's owner and group
> >    truncate(): return -EINVAL
> > 
> > Not only would this solve your "mmap of shared memory" problem, it would
> > become possible to view and edit shared memory using "cat", "hexdump" and
> > "vi". Benefits of the "everything is a file" philosophy.
> 
> Don't do it in procfs. Make a separate filesystem and mount it on the
> empty directory in /proc, if you really need it (I'ld rather use some
> other location - even /dev/shm would be better). This filesystem will have
> _nothing_ with proc in terms of code. There is enough mess in procfs
> already. Keep this one separate.

I totally agree. After looking at the shm code I concluded that making
a filesystem out of it will cleanup the code a lot. There is much
duplication of code from the mm layer.

I am just working on this filesystem.

Greetings
          Christoph

-- 
Christoph Rohland
SAP AG           
LinuxLab                        Email: hans-christoph.rohland@sap.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://humbolt.geo.uu.nl/Linux-MM/