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Re: "ERROR: latch already owned" on gharial

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Noah Misch <noah@leadboat.com>, Andres Freund <andres@anarazel.de>, CM Team <cm@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-05-26T01:50:00Z
Lists: pgsql-hackers 
On Thu, May 26, 2022 at 2:25 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Noah Misch <noah@leadboat.com> writes:
> > +1, this is at least the third non-obvious miscompilation from gharial.
>
> Is there any evidence that this is a compiler-sourced problem?
> Maybe it is, but it's sure not obvious to me (he says, eyeing his
> buildfarm animals with even older gcc versions).

Sorry for the ambiguity -- I have no evidence of miscompilation.  My
"just BTW" paragraph was a reaction to the memory of the last couple
of times Noah and I wasted hours chasing red herrings on this system,
which is pretty demotivating when looking into an unexplained failure.

On a more practical note, I don't have access to the BF database right
now.  Would you mind checking if "latch already owned" has occurred on
any other animals?

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 debugging help in OwnLatch().

  2. Add barriers to the latch code.