Date: Mon, 28 Jan 2019 16:40:36 -0800
From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>,
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>,
	Amit Kapila <amit.kapila16@gmail.com>
Subject: Re: Why are we PageInit'ing buffers in RelationAddExtraBlocks()?
Message-ID: <20190129004036.c2cf3fxoescf2rvf@alap3.anarazel.de>
References: <13071.1545266373@sss.pgh.pa.us>
 <20181220005636.cowkudhiu666mhdi@alap3.anarazel.de>
 <20181220230411.zzwioucrg7d3ld2m@alap3.anarazel.de>
 <20190115204428.kpqmk3ix6cenr7gi@alap3.anarazel.de>
 <11587.1547591721@sss.pgh.pa.us>
 <20190128213346.ie6zbwiddgnfd37l@alap3.anarazel.de>
 <20190128221055.nddkrusu3u5263qo@alap3.anarazel.de>
 <20190128222259.zhi7ovzgtkft6em6@alap3.anarazel.de>
 <26263.1548716939@sss.pgh.pa.us>
 <20190128234933.ioateictsk3qmsuf@alap3.anarazel.de>
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Hi,

On 2019-01-28 15:49:33 -0800, Andres Freund wrote:
> On 2019-01-28 18:08:59 -0500, Tom Lane wrote:
> > Andres Freund <andres@anarazel.de> writes:
> > > I'm inclined to put back the
> > >            LockBuffer(buf, BUFFER_LOCK_UNLOCK);
> > >            LockRelationForExtension(onerel, ExclusiveLock);
> > >            UnlockRelationForExtension(onerel, ExclusiveLock);
> > >            LockBufferForCleanup(buf);
> > >            if (PageIsNew(page))
> > > dance regardless, just to get the buildfarm to green?
> > 
> > The buildfarm's got half a dozen reports now of a failure of this ilk,
> > so you'd better do something.
> 
> Yea, I was working on a patch. Was trying to come up with an explanation
> of how this can be realistically hit on the BF, but failed.  I've pushed
> something now, let's see whether that fixes it.

It has not. Given that I don't understand what's happening here I'm
going to revert both commits unless I figure it out in the next ~30min.

Greetings,

Andres Freund