From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thomas Munro <thomas.munro@gmail.com>
cc: Noah Misch <noah@leadboat.com>, Andrey Borodin <x4mmm@yandex-team.ru>,
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        Michael Paquier <michael@paquier.xyz>, Peter Geoghegan <pg@bowt.ie>,
        Andres Freund <andres@anarazel.de>
Subject: Re: conchuela timeouts since 2021-10-09 system upgrade
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Comments: In-reply-to Thomas Munro <thomas.munro@gmail.com>
	message dated "Fri, 19 Nov 2021 22:07:42 +1300"
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Date: Fri, 19 Nov 2021 09:56:31 -0500
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Thomas Munro <thomas.munro@gmail.com> writes:
> On Fri, Nov 19, 2021 at 7:13 PM Noah Misch <noah@leadboat.com> wrote:
>> Looks like optimal material for a kernel bug report.  Excellent discovery.

> https://bugs.dragonflybsd.org/issues/3307

I see they're pushing back on whether this is a bug.  I failed to find a
way to quickly comment on the bug report, but I suggest you quote POSIX
select(2) at them:

    A descriptor shall be considered ready for reading when a call to an
    input function with O_NONBLOCK clear would not block, whether or not
    the function would transfer data successfully. (The function might
    return data, an end-of-file indication, or an error other than one
    indicating that it is blocked, and in each of these cases the
    descriptor shall be considered ready for reading.)

    A descriptor shall be considered ready for writing when a call to an
    output function with O_NONBLOCK clear would not block, whether or not
    the function would transfer data successfully.

I don't know whether it'd help to point out that the test program works
as expected on other BSDen.  (I'm planning to go try it on a few more
platforms in a bit, but in any case the standards-compliance question
looks pretty open-and-shut to me.)

			regards, tom lane