Re: Overcommitable memory??

From: Horst von Brand (vonbrand@pincoya.inf.utfsm.cl)
Date: Tue Mar 21 2000 - 13:34:20 EST


"Rask Ingemann Lambertsen" <rask-linux@kampsax.k-net.dk> said:
> Den 20-Mar-00 18:44:28 skrev Horst von Brand følgende om "Re: Overcommitable memory?? ":
> > Jesse Pollard <pollard@cats-chateau.net> said:

> > [...]

> >> YOU ARN'T OOM - a specific user is out of resources, not a catastrophic
> >> failure.

> > If the user's programs get killed, they'll be pissed off.

> And for a good reason too. So don't kill the user's programs. That's why
> Jesse and others would really like per user memory quotas, just as you have
> per user disk space quotas.

What _do_ you do then if Jane runs over her memory quota?

> If you can disable overcommit, the program is
> in control of what happens when it can't get the amount of memory it would
> like. If you also add per user memory quotas, the system administrator can
> prevent a single user (or another finite number of users) from using all
> memory.

There are several points where memory is allocated, f.ex. expanding the
stack. There is simply no way in Unix to intercept that sanely AFAIKS, so
the "nice proggie steps down on memory use" isn't always possible anyway.

BTW, could you please point at a clean example of a program in actual use
that handles freeing up memory when OOM looms? Would be useful to have
handy...

-- 
Dr. Horst H. von Brand                       mailto:vonbrand@inf.utfsm.cl
Departamento de Informatica                     Fono: +56 32 654431
Universidad Tecnica Federico Santa Maria              +56 32 654239
Casilla 110-V, Valparaiso, Chile                Fax:  +56 32 797513

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Thu Mar 23 2000 - 21:00:34 EST