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

[Andrey M. Borodin]

> On 8 Nov 2023, at 14:17, Ants Aasma <a...@cybertec.at> wrote:
> 
> Is there a particular reason why lock partitions need to be bigger? We have 
> one lock per buffer anyway, bankwise locks will increase the number of locks 
> < 10%.

The problem was not attracting much attention for some years. So my reasoning 
was that solution should not have any costs at all. Initial patchset with banks 
did not add any memory footprint.


> On 8 Nov 2023, at 14:17, Ants Aasma <a...@cybertec.at> wrote:
> 
> I am working on trying out a SIMD based LRU mechanism that uses a 16 entry 
> bank. 

FWIW I tried to pack struct parts together to minimize cache lines touched, see 
step 3 in [0]. So far I could not prove any performance benefits of this 
approach. But maybe your implementation will be more efficient.


Thanks!


Best regards, Andrey Borodin.


[0] 
https://www.postgresql.org/message-id/93236d36-b91c-4dfa-af03-99c083840...@yandex-team.ru