Re: pgsql: Add function to get memory context stats for processes

On Tue, Apr 15, 2025 at 6:11 AM Andres Freund <andres@anarazel.de> wrote:
> There very well could be a CFI - but it better be somewhere where the
> in-memory state is consistent. Otherwise an error inside raised in the CFI
> would lead the in-memory state inconsistent which then would cause problems
> when cleaning up the dsa during resowner release or process exit.
>
> What am I missing here?

I think maybe you're only thinking about gathering the data. What
about publishing it? If the DSA code were interrupted at a CFI and the
interrupting code went and tried to perform a DSA allocation to store
the resulting data and then returned to the interrupted DSA operation,
would you expect the code to cope with that? I do not believe we have
anywhere enough guarantees about reentrancy for that to be safe.

--
Robert Haas
EDB: http://www.enterprisedb.com