From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jignesh K. Shah <J.K.Shah@Sun.COM>
Cc: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-performance@postgresql.org, Alvaro Herrera <alvherre@commandprompt.com>
Subject: Re: User concurrency thresholding: where do I look?
Date: Fri, 20 Jul 2007 16:16:01 -0400
Message-ID: <14909.1184962561@sss.pgh.pa.us> (raw)
In-Reply-To: <46A11116.5030905@sun.com>
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<200707192138.39679.josh@agliodbs.com>
<46A0FA31.2080208@sun.com>
<12002.1184955831@sss.pgh.pa.us>
<46A1055F.9010304@sun.com>
<12445.1184958793@sss.pgh.pa.us>
<46A11116.5030905@sun.com>
"Jignesh K. Shah" <J.K.Shah@Sun.COM> writes:
> Tom Lane wrote:
>> So follow that up --- try to determine which lock is being contended
>> for. There's some very crude code in the sources that you can enable
>> with -DLWLOCK_STATS, but probably DTrace would be a better tool.
> Using plockstat -A -s 5 -p $pid
I don't know what that is, but it doesn't appear to have anything to do
with Postgres LWLocks or spinlocks, which are the locks I was thinking of.
Try asking Robert Lor about this --- IIRC he had some dtrace probes to
work with our locks.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, J.K.Shah@Sun.COM, josh@agliodbs.com, alvherre@commandprompt.com
Subject: Re: User concurrency thresholding: where do I look?
In-Reply-To: <14909.1184962561@sss.pgh.pa.us>
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