Re: Add bump memory context type and use it for tuplesorts - Mailing list pgsql-hackers

From David Rowley
Subject Re: Add bump memory context type and use it for tuplesorts
Date
Msg-id CAApHDvoOcNzDcVtyiggrrg6nt+M4NHwMjzM0k+az8qGFHEcB9Q@mail.gmail.com
Whole thread Raw
In response to Re: Add bump memory context type and use it for tuplesorts  (Tomas Vondra <tomas.vondra@enterprisedb.com>)
Responses Re: Add bump memory context type and use it for tuplesorts
List pgsql-hackers
On Tue, 12 Mar 2024 at 12:25, Tomas Vondra
<tomas.vondra@enterprisedb.com> wrote:
> (b) slab is considerably slower

It would be interesting to modify SlabReset() to, instead of free()ing
the blocks, push the first SLAB_MAXIMUM_EMPTY_BLOCKS of them onto the
emptyblocks list.

That might give us an idea of how much overhead comes from malloc/free.

Having something like this as an option when creating a context might
be a good idea.  generation.c now keeps 1 "freeblock" which currently
does not persist during context resets. Some memory context usages
might suit having an option like this.  Maybe something like the
executor's per-tuple context, which perhaps (c|sh)ould be a generation
context...  However, saying that, I see you measure it to be slightly
slower than aset.

David



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