From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alexander Lakhin <exclusion@gmail.com>
cc: Michael Banck <mbanck@gmx.net>, pgsql-hackers@lists.postgresql.org,
        Michael Paquier <michael@paquier.xyz>,
        Thomas Munro <thomas.munro@gmail.com>
Subject: Re: GNU/Hurd portability patches
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Comments: In-reply-to Alexander Lakhin <exclusion@gmail.com>
	message dated "Wed, 24 Sep 2025 18:00:00 +0300"
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Date: Wed, 24 Sep 2025 11:37:51 -0400
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Alexander Lakhin <exclusion@gmail.com> writes:
> 24.09.2025 13:45, Michael Banck wrote:
>> How much timer resolution do we require from the system? GNU Mach seems
>> to (at least try to) guarantee that the timer won't go backwards, but it
>> does not guarantee (currently) that two consecutive clock_gettime()
>> calls will return something different in all cases.

> Regarding the lowest timer resolution, as I mentioned at [3], 32k_counter
> gives only 0.030517 sec...

We are currently doing a short pg_test_timing run in every BF run,
but with only a cursory regex-based sanity check on the output.
Since it's a TAP test, we could easily report the full output in
the TAP log without causing problems.  I was already thinking about
doing that, and if there's some question about the minimum expected
timer resolution then it's really silly to not be capturing that
data.

I will go do that, and in a few day's time we should have enough
reports to see what we can realistically expect.

			regards, tom lane