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

David Rowley <dgrowleyml@gmail.com>

From: David Rowley <dgrowleyml@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, Yura Sokolov <y.sokolov@postgrespro.ru>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2022-09-06T02:35:52Z
Lists: pgsql-hackers
On Tue, 6 Sept 2022 at 14:32, David Rowley <dgrowleyml@gmail.com> wrote:
> I wonder if there are many usages of MemoryContextContains in
> extensions. If there's not, I'd be much happier if we got rid of this
> function and used GetMemoryChunkContext() in nodeAgg.c and
> nodeWindowAgg.c.

I see postgis is one user of it, per [1].  The other extensions
mentioned there just seem to be copying code and not using it.

David

[1] https://codesearch.debian.net/search?q=MemoryContextContains&literal=1



Commits

  1. Harden memory context allocators against bogus chunk pointers.

  2. Improve our ability to detect bogus pointers passed to pfree et al.

  3. Remove MemoryContextContains().

  4. Remove uses of MemoryContextContains in nodeAgg.c and nodeWindowAgg.c.

  5. Temporarily make MemoryContextContains return false

  6. Make MemoryContextContains work correctly again

  7. Make more effort to put a sentinel at the end of allocated memory

  8. Fix some possibly latent bugs in slab.c

  9. Various cleanups of the new memory context header code

  10. Revert "Add missing padding from MemoryChunk struct"

  11. Use MAXALIGN() in calculations using sizeof(SlabBlock)

  12. Add missing padding from MemoryChunk struct

  13. Improve performance of and reduce overheads of memory management