Re: "multiple backends attempting to wait for pincount 1"

On 2015-02-13 00:27:04 -0500, Tom Lane wrote:
> Two different CLOBBER_CACHE_ALWAYS critters recently reported exactly
> the same failure pattern on HEAD:
>
> http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=markhor&dt=2015-02-06%2011%3A59%3A59
> http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=tick&dt=2015-02-12%2010%3A22%3A57

Those are rather strange, yea.

Unfortunately both report a relatively large number of changes since the
last run...

> I'd say we have a problem. I'd even go so far as to say that somebody has
> completely broken locking, because this looks like autovacuum and manual
> vacuuming are hitting the same table at the same time.

Hm. It seems likely that that would show up more widely.

Oddly enough other CLOBBER_CACHE animals, like
http://pgbuildfarm.org/cgi-bin/show_log.pl?nm=jaguarundi&dt=2015-02-12%2013%3A03%3A00
, that run more frequently have not reported a problem. Neither has
leech which IIRC runs on the same system...

One avenue to look are my changes around both buffer pinning and
interrupt handling...

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
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