Re: Improve logging when using Huge Pages

Michael Paquier <michael@paquier.xyz>

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
Date: 2023-03-20T05:03:13Z
Lists: pgsql-hackers
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

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Add GUC parameter "huge_pages_status"

  2. Add check on initial and boot values when loading GUCs

  3. Clean up some inconsistencies with GUC declarations

  4. Clean up some GUC declarations and comments