Feedback-ID: i0fe9450f:Fastmail
Date: Mon, 20 Mar 2023 14:03:13 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: sfrost@snowman.net, pryzby@telsasoft.com, alvherre@alvh.no-ip.org,
	andres@anarazel.de, nathandbossart@gmail.com,
	jchampion@timescale.com, john.naylor@enterprisedb.com,
	masao.fujii@oss.nttdata.com, noriyoshi.shinoda@hpe.com,
	pgsql-hackers@postgresql.org, rjuju123@gmail.com,
	sawada.mshk@gmail.com, tgl@sss.pgh.pa.us, thomas.munro@gmail.com
Subject: Re: Improve logging when using Huge Pages
Message-ID: <ZBfpEYG0qTCiBGDh@paquier.xyz>
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On Mon, Mar 20, 2023 at 01:54:46PM +0900, Michael Paquier wrote:
> The main advantage of a read-only GUC over a function is that users
> would not need to start a postmaster to know if huge pages would be
> active or not.  This is the main reason why a GUC would be a better
> fit, in my opinion, because it makes for a cheaper check, while still
> allowing a SQL query to check the value of the GUC.

[ Should have read more carefully ]

..  Which is something you cannot do with -C because mmap() happens
after the runtime-computed logic for postgres -C.  It does not sound
right to do the mmap() for a GUC check, so indeed a function may be
more adapted rather than move mmap() call a bit earlier in the
postmaster startup sequence.
--
Michael

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