Horton

Re: problems with "Shared Memory and Semaphores" section of docs

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: "Imseih (AWS), Sami" <simseih@amazon.com>, Tom Lane <tgl@sss.pgh.pa.us>, Justin Pryzby <pryzby@telsasoft.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2024-06-06T19:31:53Z
Lists: pgsql-hackers 
On Thu, Jun 6, 2024 at 3:21 PM Nathan Bossart <nathandbossart@gmail.com> wrote:
> Here is a rebased version of the patch for v18 that adds a runtime-computed
> GUC.  As I noted earlier, there still isn't a consensus on this approach.

I don't really like making this a GUC, but what's the other option?
It's reasonable for people to want to ask the server how many
resources it will need to start, and -C is the only tool we have for
that right now. So I feel like this is a fair thing to do.

I do think the name could use some more thought, though.
semaphores_required would end up being the same kind of thing as
shared_memory_size_in_huge_pages, but the names seem randomly
different. If semaphores_required is right here, why isn't
shared_memory_required used there? Seems more like we ought to call
this semaphores or os_semaphores or num_semaphores or
num_os_semaphores or something.

-- 
Robert Haas
EDB: http://www.enterprisedb.com

Commits

  1. Introduce num_os_semaphores GUC.

  2. Fix documentation for POSIX semaphores.

  3. Fix documentation for System V semaphores.