Re: Move PinBuffer and UnpinBuffer to atomics - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Move PinBuffer and UnpinBuffer to atomics
Date
Msg-id 20160405144503.xlv6sjvuzu5e5ppn@alap3.anarazel.de
Whole thread Raw
In response to Re: Move PinBuffer and UnpinBuffer to atomics  (Alexander Korotkov <a.korotkov@postgrespro.ru>)
Responses Re: Move PinBuffer and UnpinBuffer to atomics  (Amit Kapila <amit.kapila16@gmail.com>)
Re: Move PinBuffer and UnpinBuffer to atomics  (Alexander Korotkov <a.korotkov@postgrespro.ru>)
List pgsql-hackers
On 2016-04-05 17:36:49 +0300, Alexander Korotkov wrote:
> Could the reason be that we're increasing concurrency for LWLock state
> atomic variable by placing queue spinlock there?

Don't think so, it's the same cache-line either way.

> But I wonder why this could happen during "pgbench -S", because it doesn't
> seem to have high traffic of exclusive LWLocks.

Yea, that confuses me too. I suspect there's some mis-aligned
datastructures somewhere. It's hard to investigate such things without
access to hardware.

(FWIW, I'm working on getting pinunpin committed)

Greetings,

Andres Freund



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