Re: SLRU optimization - configurable buffer pool and partitioning the SLRU lock

On Tue, Jan 2, 2024 at 7:53 PM Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> On Fri, Dec 22, 2023 at 8:14 AM Andrey M. Borodin <x4mmm(at)yandex-team(dot)ru> wrote:
> > Just a side node.
> > It seems like commit log is kind of antipattern of data contention. Even when we build a super-optimized SLRU. Nearby **bits** are written by different CPUs.
> > I think that banks and locks are good thing. But also we could reorganize log so that
> > status of transaction 0 is on a page 0 at bit offset 0
> > status of transaction 1 is on a page 1 at bit offset 0
> > status of transaction 2 is on a page 2 at bit offset 0
> > status of transaction 3 is on a page 3 at bit offset 0
> > status of transaction 4 is on a page 0 at bit offset 2
> > status of transaction 5 is on a page 1 at bit offset 2
> > status of transaction 6 is on a page 2 at bit offset 2
> > status of transaction 7 is on a page 3 at bit offset 2
> > etc...
>
> This is an interesting idea. A variant would be to stripe across
> cachelines within the same page rather than across pages. If we do
> stripe across pages as proposed here, we'd probably want to rethink
> the way the SLRU is extended -- page at a time wouldn't really make
> sense, but preallocating an entire file might.

Yeah, this is indeed an interesting idea. So I think if we are
interested in working in this direction maybe this can be submitted in
a different thread, IMHO.

--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com