Re: "ERROR: latch already owned" on gharial

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thomas Munro <thomas.munro@gmail.com>
Cc: Noah Misch <noah@leadboat.com>, Andres Freund <andres@anarazel.de>, CM Team <cm@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-05-26T02:35:06Z
Lists: pgsql-hackers
Thomas Munro <thomas.munro@gmail.com> writes:
> 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.

I can't deny that those HPUX animals have produced more than their
fair share of problems.

> 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?

Looking back 6 months, these are the only occurrences of that string
in failed tests:

 sysname | branch |      snapshot       |     stage      |                                 l                                 
---------+--------+---------------------+----------------+-------------------------------------------------------------------
 gharial | HEAD   | 2022-04-28 23:37:51 | Check          | 2022-04-28 18:36:26.981 MDT [22642:1] ERROR:  latch already owned
 gharial | HEAD   | 2022-05-06 11:33:11 | IsolationCheck | 2022-05-06 10:10:52.727 MDT [7366:1] ERROR:  latch already owned
 gharial | HEAD   | 2022-05-24 06:31:31 | IsolationCheck | 2022-05-24 02:44:51.850 MDT [13089:1] ERROR:  latch already owned
(3 rows)


			regards, tom lane



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.