From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
cc: Merlin Moncure <mmoncure@gmail.com>, Jim Nasby <jim@nasby.net>,
	Andres Freund <andres@2ndquadrant.com>,
	Jeff Janes <jeff.janes@gmail.com>, Ants Aasma <ants@cybertec.at>,
	Atri Sharma <atri.jiit@gmail.com>, Greg Stark <stark@mit.edu>,
	Amit Kapila <amit.kapila@huawei.com>,
	PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: Page replacement algorithm in buffer cache
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Comments: In-reply-to Robert Haas <robertmhaas@gmail.com>
	message dated "Tue, 02 Apr 2013 11:54:32 -0400"
Date: Tue, 02 Apr 2013 12:22:03 -0400
Message-ID: <3236.1364919723@sss.pgh.pa.us>
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Sender: pgsql-hackers-owner@postgresql.org

Robert Haas <robertmhaas@gmail.com> writes:
> But, having said that, I still think the best idea is what Andres
> proposed, which pretty much matches my own thoughts: the bgwriter
> needs to populate the free list, so that buffer allocations don't have
> to wait for linear scans of the buffer array.  That's just plain too
> slow.

I agree in general, though I'm not sure the bgwriter process can
reasonably handle this need along with what it's already supposed to be
doing.  We may need another background process that is just responsible
for keeping the freelist populated.

			regards, tom lane


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