Re: Reducing the chunk header sizes on all memory context types

On Tue, 11 Oct 2022 at 08:35, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Hearing no comments on that, I decided that a good policy would be
> to use Asserts in the paths dealing with small chunks but test-and-elog
> in the paths dealing with large chunks.

This seems like a good policy. I think it's good to get at least the
Asserts in there. If we have any troubles in the future then we can
revisit this and reconsider if we need to elog them instead.

> Hence v2 attached, which cleans things up a tad in aset.c and then
> extends similar policy to generation.c and slab.c.

Looking at your changes to SlabFree(), I don't really think that
change is well aligned to the newly proposed policy. My understanding
of the rationale behind this policy is that large chunks get malloced
and will be slower anyway, so the elog(ERROR) is less overhead for
those. In SlabFree(), we're most likely not doing any free()s, so I
don't quite understand why you've added the elog rather than the
Assert for this case. The slab allocator *should* be very fast.

I don't have any issue with any of the other changes.

David