Date: Fri, 8 Mar 2019 17:26:15 +0100
From: Peter <pmc@citylink.dinoex.sub.org>
To: Andrew Gierth <andrew@tao11.riddles.org.uk>
Cc: pgsql-admin@postgresql.org, pgsql@FreeBSD.org
Subject: Re: Upgrade 10.5->10.6 : db crash BUS ERROR (sig 10), reproducible
Message-ID: <20190308162615.GB50588@gate.oper.dinoex.org>
References: <20190308012012.GA49481@gate.oper.dinoex.org>
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On Fri, Mar 08, 2019 at 02:35:33AM +0000, Andrew Gierth wrote:

! Yes, the database is supposed to be able to run without SSE2, as long as
! it is built with gcc and not clang, and without any architecture flags
! that imply SSE2 support.

Okay, thank You, thats what I was worrying - as some developers make a
strategic decision here.
 
! I'm pretty sure nothing in our buildfarm is i386 without SSE2 though.

*laugh* no problem with that. There probably wouldn't be any reason
to have such. 
Here I have a couple of good reasons: that machine does for what
other people buy a little plastic box from the shelf called internet 
access router - and besides being stupid, these pieces are full of 
bugs and get hacked (I doubt anybody would bother to write a spectre 
exploit for pentium3, although it should be possible).
And on the other side, this is a server board built for 365/24 
running on regECC mem. A new one of that class would inevitably carry 
quite a big Xeon, and so would do nothing than idle here. I see no 
point in such investment, at least not until Intel comes up with a
really nice new design getting rid of the crap.
https://www.techradar.com/news/spoiler-flaw-in-intel-cpus-is-similar-to-spectre-yet-dangerously-different

!  Peter> Whateever information You like to have, just ask and I will
!  Peter> gladly do my best to obtain it, as I get around. (This is a
!  Peter> reproducible on a very well maintained piece of software - this
!  Peter> is rather fun.)
! 
! Your backtrace implies that you are running with checksums enabled;
! true?

Correct.

!  Peter> The crash happens at a specific query - I get parse,bind, but no
!  Peter> execute timing.
! 
! What is the exact query?

This will be some work. It includes about six different sql functions
(and some of these are probably also old enough to vote).

! I'm doing some investigations of my own, I may have more questions
! later.

You're welcome.

rgds,
PMc