From: Andres Freund <andres@2ndquadrant.com>
To: Merlin Moncure <mmoncure@gmail.com>
Cc: Дмитрий Дегтярёв <degtyaryov@gmail.com>
Cc: postgres performance list <pgsql-performance@postgresql.org>
Subject: Re: Cpu usage 100% on slave. s_lock problem.
Date: Tue, 27 Aug 2013 17:55:56 +0200
Message-ID: <20130827155556.GA9061@awork2.anarazel.de> (raw)
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On 2013-08-27 09:57:38 -0500, Merlin Moncure wrote:
> + bool
> + RecoveryMightBeInProgress(void)
> + {
> + /*
> + * We check shared state each time only until we leave recovery mode. We
> + * can't re-enter recovery, so there's no need to keep checking after the
> + * shared variable has once been seen false.
> + */
> + if (!LocalRecoveryInProgress)
> + return false;
> + else
> + {
> + /* use volatile pointer to prevent code rearrangement */
> + volatile XLogCtlData *xlogctl = XLogCtl;
> +
> + /* Intentionally query xlogctl without spinlocking! */
> + LocalRecoveryInProgress = xlogctl->SharedRecoveryInProgress;
> +
> + return LocalRecoveryInProgress;
> + }
> + }
I don't think it's acceptable to *set* LocalRecoveryInProgress
here. That should only be done in the normal routine.
Greetings,
Andres Freund
--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
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To: pgsql-performance@postgresql.org
Cc: andres@2ndquadrant.com, mmoncure@gmail.com, degtyaryov@gmail.com
Subject: Re: Cpu usage 100% on slave. s_lock problem.
In-Reply-To: <20130827155556.GA9061@awork2.anarazel.de>
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