Re: [RFC] What to do on VM exhaustion

[Michael Snyder <michsnyd@cisco.com>]

Paul Koning wrote:
>>>>>>"Michael" == Michael Snyder <michsnyd@cisco.com> writes:
> 
> 
>  Michael> Hey folks, I don't know how many of you may have ever run
>  Michael> into this situation, but my question is, what should we do
>  Michael> in gdb when we detect that we are dead out of memory?
> 
>  Michael> Theoretically it's handled -- there is a routine in utils.c
>  Michael> called "nomem", which calls internal_error.  The problem is
>  Michael> that internal_error isn't a simple bailout -- it calls query
>  Michael> to ask the user what s/he wants to do.  And you can't count
>  Michael> on something like that working, when you are out of virtual
>  Michael> memory.
> 
> That's for sure.  And it fails miserably.  GDB hangs for a while then
> blows up spectacularly.
> 
>  Michael> I actually ran into this once before, years ago -- in fact
>  Michael> it was RMS himself who called me to beef about gdb bailing
>  Michael> on him, when he was debugging emacs and crashed the stack
>  Michael> with an infinite recursion.  I think gdb ran out of memory
>  Michael> while trying to do a backtrace.  He wanted me to make it
>  Michael> recover gracefully and let him keep debugging.  I couldn't
>  Michael> do it, but then I didn't have the luxury of having all you
>  Michael> guys to ask for advice!
> 
>  Michael> In present time, I'm suggesting that nomem should just write
>  Michael> a simple error msg to the console and abort.  What do you
>  Michael> think?
> 
> That would be an improvement over the current broken situation.  The
> right answer is what RMS said, though.  Unfortunately that's likely to
> be hard.

Yeah, well, until someone's willing to implement garbage collection...
;-/