[PATCH 0/2] Demangler crash handler

[Florian Weimer]

* Gary Benson:

>> It would be more reliable to run the demangler in a separate
>> process.
>
> Agreed.  There are two issues though.  First is performance:
> GDB can demangle a lot of symbols--starting GDB on LibreOffice
> demangles more than 369,000 symbols on my machine, and typing
> "b <Tab><Tab>" demangles 2,740,000 more--so the IPC overhead
> has to be seriously low.

Is most of the demangling of the bulk kind?  These cases are easy in
the sense that a ping-pong between the two processes is avoidable.

More worrisome would be the occasional demangling as part of other
tasks, where the context switches might become very visible.

>> What's so difficult about fixing the demangler?
>
> It's not so difficult really, but fixes take time to diagnose,
> reproduce, fix, test, review, etc.

I was referring to a more permanent fix, not just patching the bug of
the day as users encounter it.

> During that interval the user cannot use GDB to debug their program.
> This patch is about allowing the user the possibility of getting
> their work done.

I suppose I could run the demangler on all symbols in Fedora and
downstream and see what breaks.  Would that help?