Re: hung backends stuck in spinlock heavy endless loop - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: hung backends stuck in spinlock heavy endless loop
Date
Msg-id CAM3SWZQmAWR0Z6MgQMYzAGgzRGC498CCnJih18bj7Ydat4c93A@mail.gmail.com
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In response to Re: hung backends stuck in spinlock heavy endless loop  (Andres Freund <andres@2ndquadrant.com>)
Responses Re: hung backends stuck in spinlock heavy endless loop
Re: hung backends stuck in spinlock heavy endless loop
List pgsql-hackers
On Tue, Jan 13, 2015 at 3:21 PM, Andres Freund <andres@2ndquadrant.com> wrote:
> My guess is rather that it's contention on the freelist lock via
> StrategyGetBuffer's. I've seen profiles like this due to exactly that
> before - and it fits to parallel loading quite well.

I'm not saying you're wrong, but the breakdown of _bt_moveright()
relative to _bt_relandgetbuf() calls seems a bit fishy to me.

I don't remember seeing _bt_moveright()  or _bt_compare() figuring so
prominently, where _bt_binsrch() is nowhere to be seen. I can't see a
reference to _bt_binsrch() in either profile.

-- 
Peter Geoghegan



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