Re: Fix bank selection logic in SLRU - Mailing list pgsql-hackers

From Dilip Kumar
Subject Re: Fix bank selection logic in SLRU
Date
Msg-id CAFiTN-uZXxsnZu5OGNqpP137pzv2yB0u0kSdZiPHkWUA9epDQQ@mail.gmail.com
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In response to Re: Fix bank selection logic in SLRU  ("Andrey M. Borodin" <x4mmm@yandex-team.ru>)
Responses Re: Fix bank selection logic in SLRU
Re: Fix bank selection logic in SLRU
List pgsql-hackers
On Tue, 10 Dec 2024 at 7:24 PM, Andrey M. Borodin <x4mmm@yandex-team.ru> wrote:


> On 10 Dec 2024, at 16:26, Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> IIUC, we do check that it should be in multiple of bank size (i.e.)
> which is multiple of 2, right?  Am I missing something?

Bank selection code assumes that number of buffers is power of 2.
If the number of buffers is not power of 2 - only subset of buffers will be used. In worst case, e.g. 65 buffers, everything will be buffered only in bank 64.

But why that would be the case? the acceptable values for GUC to configure the slru buffers are in multiple of 16(bank size) we have that check to check the GUC values.

Dilip

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