Re: Estimating HugePages Requirements?

Nathan Bossart <bossartn@amazon.com>

From: "Bossart, Nathan" <bossartn@amazon.com>
To: Fujii Masao <masao.fujii@oss.nttdata.com>, Michael Paquier <michael@paquier.xyz>
Cc: Justin Pryzby <pryzby@telsasoft.com>, Andres Freund <andres@anarazel.de>, Magnus Hagander <magnus@hagander.net>, Mark Dilger <mark.dilger@enterprisedb.com>, Don Seiler <don@seiler.us>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2021-09-08T17:52:33Z
Lists: pgsql-hackers

Attachments

On 9/8/21, 12:11 AM, "Fujii Masao" <masao.fujii@oss.nttdata.com> wrote:
> Thanks for adding useful feature!

:)

> +               {"shared_memory_size", PGC_INTERNAL, RESOURCES_MEM,
>
> When reading the applied code, I found the category of shared_memory_size
> is RESOURCES_MEM. Why? This seems right because the parameter is related
> to memory resource. But since its context is PGC_INTERNAL, PRESET_OPTIONS
> is more proper as the category? BTW, the category of any other
> PGC_INTERNAL parameters seems to be PRESET_OPTIONS.

Yeah, I did wonder about this.  We're even listing it in the "Preset
Options" section in the docs.  I updated this in the new patch set,
which is attached.

Nathan

Commits

  1. Silence extra logging when using "postgres -C" on runtime-computed GUCs

  2. doc: Improve postgres command for shared_memory_size_in_huge_pages

  3. Introduce GUC shared_memory_size_in_huge_pages

  4. Support "postgres -C" with runtime-computed GUCs

  5. Make shared_memory_size a preset option

  6. Introduce GUC shared_memory_size

  7. Move the shared memory size calculation to its own function

  8. Add new GUC, max_worker_processes, limiting number of bgworkers.