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In-Reply-To: <0CD98EB5-71AC-4D84-BC90-93674B6330F4@yandex-team.ru>
From: Thomas Munro <thomas.munro@gmail.com>
Date: Tue, 16 Nov 2021 10:23:02 +1300
Message-ID: 
 <CA+hUKGJHA24SFAQureqf0EodkXv0W0hAZybcU9OpZAp3O2uegQ@mail.gmail.com>
Subject: Re: conchuela timeouts since 2021-10-09 system upgrade
To: Andrey Borodin <x4mmm@yandex-team.ru>
Cc: Noah Misch <noah@leadboat.com>,
	PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>,
 Michael Paquier <michael@paquier.xyz>,
	Tom Lane <tgl@sss.pgh.pa.us>, Peter Geoghegan <pg@bowt.ie>,
 Andres Freund <andres@anarazel.de>
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On Mon, Nov 15, 2021 at 8:20 PM Andrey Borodin <x4mmm@yandex-team.ru> wrote:
> I've sent some diagnostics info to Thomas offlist, but I do not understand how it can be used...

Summary for the record: defunct child, and gdb showed perl blocked in
select(), and ps revealed that Dragonfly internally maps select() onto
kevent() (wchan = kqread), which is interesting, but apparently not
new.  (Hmmm, /me eyes the recent changes to events reported on
half-closed pipes[1].)

[1] https://github.com/DragonFlyBSD/DragonFlyBSD/commits/master/sys/kern/sys_generic.c