Re: pgbench test failing on 14beta1 on Debian/i386 - Mailing list pgsql-hackers

From Thomas Munro
Subject Re: pgbench test failing on 14beta1 on Debian/i386
Date
Msg-id CA+hUKGJri_OK6VSk56NVOyfYRKOQs1B6nDpCUPo12jiRxJ1Jsw@mail.gmail.com
Whole thread Raw
In response to Re: pgbench test failing on 14beta1 on Debian/i386  (Thomas Munro <thomas.munro@gmail.com>)
Responses Re: pgbench test failing on 14beta1 on Debian/i386
List pgsql-hackers
On Wed, May 19, 2021 at 11:34 AM Thomas Munro <thomas.munro@gmail.com> wrote:
> I don't understand any of this stuff at all, but I added a bunch of
> printfs and worked out that the first point its local variables
> diverge is here:
>
>         /* Random offset */
>         r = (uint64) getrand(&random_state2, 0, size - 1);

Forgot to post the actual values:

      r = 2563421694876090368
      r = 2563421694876090365

Smells a bit like a precision problem in the workings of pg_erand48(),
but as soon as I saw floating point numbers I closed my laptop and ran
for the door.



pgsql-hackers by date:

Previous
From: Thomas Munro
Date:
Subject: Re: pgbench test failing on 14beta1 on Debian/i386
Next
From: Tom Lane
Date:
Subject: Subscription tests fail under CLOBBER_CACHE_ALWAYS