Re: Swap

[Nick LeRoy]

On Tuesday 20 November 2001 15:05, Steffen Persvold wrote:
> Christopher Friesen wrote:
> > "Richard B. Johnson" wrote:
> > > On Tue, 20 Nov 2001, Wolfgang Rohdewald wrote:
> > > > On Tuesday 20 November 2001 15:51, J.A. Magallon wrote:
> > > > > When a page is deleted for one executable (because we can re-read
> > > > > it from on-disk binary), it is discarded, not paged out.
> > > >
> > > > What happens if the on-disk binary has changed since loading the
> > > > program? -
> > >
> > > It can't. That's the reason for `install` and other methods of changing
> > > execututable files (mv exe-file exe-file.old ; cp newfile exe-file).
> > > The currently open, and possibly mapped file can be re-named, but it
> > > can't be overwritten.
> >
> > Actually, with NFS (and probably others) it can.  Suppose I change the
> > file on the server, and it's swapped out on a client that has it mounted.
> >  When it swaps back in, it can get the new information.
>
> This sounds really dangerous... What about shared libraries ??

It is.  Usually it ends with a loud 'boom' the process crashes & burns.

-Nick