Horton

Re: Estimating HugePages Requirements?

Nathan Bossart <bossartn@amazon.com>

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From: "Bossart, Nathan" <bossartn@amazon.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Fujii Masao <masao.fujii@oss.nttdata.com>, 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: 2021-09-10T23:43:40Z
Lists: pgsql-hackers 
On 9/10/21, 1:02 PM, "Robert Haas" <robertmhaas@gmail.com> wrote:
> On Thu, Sep 9, 2021 at 5:53 PM Bossart, Nathan <bossartn@amazon.com> wrote:
>> I think it might be clearer to
>> somehow indicate that the value is essentially the size of the main
>> shared memory area in terms of the huge page size, but I'm not sure
>> how to do that concisely.  Perhaps it is enough to just make sure the
>> description of "huge_pages_required" is detailed enough.
>
> shared_memory_size_in_huge_pages? It's kinda long, but a long name
> that you can understand without reading the docs is better than a
> short one where you can't.

I think that's an improvement.  The only other idea I have at the
moment is num_huge_pages_required_for_shared_memory.

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.