On Mon, Sep 27, 2021 at 9:04 PM PG Doc comments form
<noreply(at)postgresql(dot)org> wrote:
> The following documentation comment has been logged on the website:
>
> Page: https://www.postgresql.org/docs/13/kernel-resources.html
> Description:
>
> It seems that the huge_pages parameter is ignored when shared_memory_type is
> sysv. The server successfully starts with huge_pages=on, but actually
> doesn't use huge pages (relying on /proc/meminfo). I think that this is
> worth mentioning in the "Linux Huge Pages" section.
Yeah. The thread that added shared_memory_type=sysv had an unfinished
follow-up patch that stalled[1]. The goal of that patch was to add
huge page support for shared_memory_type=sysv on AIX, and it is still
waiting for testing and polishing by an AIX-enabled hacker. That
second patch included exactly such a documentation adjustment, and an
error message too (the idea was to reject that combination on Linux
but allow it on AIX). Here are those bits, extracted.
https://www.postgresql.org/message-id/flat/HE1PR0202MB28126DB4E0B6621CC6A1A91286D90%40HE1PR0202MB2812.eurprd02.prod.outlook.com