[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: how to make Debian less fragile (long and philosophical)



* Paul Michael Tevis said:

> > >     No memory cost?  Care to rethink that again?
> > 
> > I have been rethinking it, but as far as I can tell from reading the ldso
> > source and from knowing a little bit about how linkers work, there is no
> > RAM benefit from using shared libraries. The benefit is on the maintenance
> > side, having shared code sitting in a single file. If you can point me to
> > a page that explains where I'm wrong (if I am), then please do.
> 
> I forget exactly how this works.  Does Linux only maintain one in-memory
> copy of read-only data (i.e. the code and ro segments of an executable)?
> I know that various OS's do this, and I don't remember if linux does.  If
> so, then dynamically linking won't save you any RAM, since the library
> code would be ro anyway.  If not, then it might.
Linux uses copy-on-write memory pages that are shared until written, AFAIR.
And with the code residing in shared libraries it's in ro segments. I might
be wrong, but I think that's the way it is on linux.

marek

Attachment: pgpj8UqzT4xx3.pgp
Description: PGP signature


Reply to: