Re: [HACKERS] Unportable implementation of background worker start - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [HACKERS] Unportable implementation of background worker start
Date
Msg-id 9696.1493072081@sss.pgh.pa.us
Whole thread Raw
In response to Re: [HACKERS] Unportable implementation of background worker start  (Andres Freund <andres@anarazel.de>)
Responses Re: [HACKERS] Unportable implementation of background worker start  (Andres Freund <andres@anarazel.de>)
Re: [HACKERS] Unportable implementation of background worker start  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Andres Freund <andres@anarazel.de> writes:
> On 2017-04-24 17:33:39 -0400, Tom Lane wrote:
>> coypu's problem is unrelated:

> Note I was linking the 9.6 report form coypu, not HEAD. Afaics the 9.6
> failure is the same as gharial's mode of failure.

[ looks closer... ]  Oh: the 9.6 run occurred first, and the failures on
HEAD and 9.5 are presumably follow-on damage because the stuck postmaster
hasn't released semaphores.

A bit of googling establishes that NetBSD 5.1 has a broken pselect
implementation:

http://gnats.netbsd.org/cgi-bin/query-pr-single.pl?number=43625

That says they fixed it in later versions but not 5.1 :-(

I can't find any similar smoking gun on the web for HPUX, but
I'd fully expect their bug database to be behind a paywall.

What I'm inclined to do is to revert the pselect change but not the other,
to see if that fixes these two animals.  If it does, we could look into
blacklisting these particular platforms when choosing pselect.
        regards, tom lane



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