Re: [patch] tmpfs for 2.4.1

J . A . Magallon
2001-02-03T00:07:24Z

On 02.02 H. Peter Anvin wrote:
> "J . A . Magallon" wrote:
> >
> > On 02.02 Christoph Rohland wrote:
> > > "H. Peter Anvin" <hpa@zytor.com> writes:
> > >
> > > > What happened with this being a management tool for shared memory
> > > > segments?!
> > >
> > > Unfortunately we lost this ability in the 2.4.0-test series. SYSV shm
> > > now works only on an internal mounted instance and does not link the
> > > directory entry to the deleted state of the segment.
> > >
> >
> > Mmmmmm, does this mean that mounting /dev/shm is no more needed ?
> > One step more towards easy 2.2 <-> 2.4 switching...
> >
>
> In some ways it's kind of sad. I found the /dev/shm interface to be
> rather appealing :)
>

I did not get the chance to deal too much with it, but apart from moving
functionality from userspace (ipcs) to kernel (ls), what were/could be the
benefits of /dev/shm ?. Can you create a shared memory segment by simply
creating a file there, or it is just a picture of what is in kernelspace?.

First time I saw that I thought: what could happen if /dev/shm is shared
in a cluster ? or, lets suppose that /dev/shm is a logical volume made by
addition of some nfs mounted volumes, one of each node, so one piece of
the shm fs is local and other remote...kinda DSM/NUMA...?

(just too much marijuana late at night...)

--
J.A. Magallon $> cd pub
mailto:jamagallon@able.es $> more beer

Linux werewolf 2.4.1-ac1 #2 SMP Fri Feb 2 00:19:04 CET 2001 i686