Horton

Re: Estimating HugePages Requirements?

Nathan Bossart <bossartn@amazon.com>

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From: "Bossart, Nathan" <bossartn@amazon.com>
To: 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: 2021-09-08T17:48:16Z
Lists: pgsql-hackers 
On 9/7/21, 8:50 PM, "Michael Paquier" <michael@paquier.xyz> wrote:
> Switched the variable name to shared_memory_size_mb for easier
> grepping, moved it to a more correct location with the other read-only
> GUCS, and applied 0002.  Well, 0001 here.

Thanks!  And thanks for cleaning up the small mistake in aa37a43.

> +        This can be used on a running server for most parameters.  However,
> +        the server must be shut down for some runtime-computed parameters
> +        (e.g., <xref linkend="guc-huge-pages-required"/>).
> Perhaps we should add a couple of extra parameters here, like
> shared_memory_size, and perhaps wal_segment_size?  The list does not
> have to be complete, just meaningful enough.

Good idea.

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.