[Discuss] memory management

[rlk at alum.mit.edu (Robert Krawitz)]

On Mon, 22 Jun 2015 15:13:13 -0400, Matthew Gillen wrote:
> I'll chime in on this one more time just to be clear about what my beef
> with linux is here.  Several people have said, in effect, "Have more
> RAM" or "Have enough RAM for what you need".  Which is obviously true,
> but missing the point.
>
> For my day-to-day, I do have enough RAM.  What sometimes happens is that
> the cesspool of problems that is javascript engines, or eclipse, go
> completely off the rails, and start gobbling up memory.  Seeing the
> forest for the trees, what I'm getting at here is that this will always
> be an issue, and vastly over-provisioning RAM might mask the problem for
> a while, eventually your day-to-day is going to start including multiple
> VMs and you're back to square one.
>
> Operating systems have concerned themselves for a long time with not
> letting unprivileged processes destroy a system.  If a process tries to
> touch memory that doesn't belong to it, BAM! The OS says "bad process!"
> and hits it with a seg-fault.  The signal can kill the offending
> process, or the process can catch it and try to recover, but either way,
> the integrity of the rest of the system is preserved at the expense of
> not letting the naughty process do what it was trying to do.
>
> What strikes me as odd and wrong is that the OS doesn't seem to protect
> itself from thrashing.  The system is perfectly happy to render itself
> inoperative in the service of some lone process sucking up memory.

If you're concerned about that, ulimit is your friend.  Look at the
bash man page, not the man page for ulimit itself.

-- 
Robert Krawitz                                     <rlk at alum.mit.edu>

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