RE: BUG #16754: When using LLVM and parallel queries aborted all session by pg_cancel_backend.

> I don't see any plausibly-related commits since 13.1, so it's not something we recently fixed. I wonder if this is an LLVM bug fixed since the 7.1 release you have.

Thank you for your comment and test.
I tried again with an older version of LLVM below.

- PostgreSQL 13.1
- Red Hat Enterprise Linux 7.5
- LLVM 6.0
- cfe 6.0

I couldn't reproduce the problem int the above environment, so maybe it's a problem in my development environment.

Regards,
Noriyoshi Shinoda

-----Original Message-----
From: Tom Lane [mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us]
Sent: Wednesday, December 2, 2020 5:59 AM
To: Shinoda, Noriyoshi (PN Japan FSIP) <noriyoshi(dot)shinoda(at)hpe(dot)com>
Cc: pgsql-bugs(at)lists(dot)postgresql(dot)org; Andres Freund <andres(at)anarazel(dot)de>
Subject: Re: BUG #16754: When using LLVM and parallel queries aborted all session by pg_cancel_backend.

PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> SELECT pg_cancel_backend(130342);
> ...
> 2020-12-01 14:26:02.337 JST [130270] LOG: background worker "parallel
> worker" (PID 130342) was terminated by signal 11: Segmentation fault
> 2020-12-01 14:26:02.337 JST [130270] DETAIL: Failed process was running:
> EXPLAIN ANALYZE SELECT * FROM data1 d1, data1 d2;

FWIW, I failed to reproduce any crash here, using RHEL8 (llvm-10.0.1).
I don't see any plausibly-related commits since 13.1, so it's not something we recently fixed. I wonder if this is an LLVM bug fixed since the 7.1 release you have.

regards, tom lane