Message-ID: <49D7AD08.5080202@agliodbs.com>
Date: Sat, 04 Apr 2009 11:55:04 -0700
From: Josh Berkus <josh@agliodbs.com>
Organization: Aglio Database Solutions
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To: Greg Smith <gsmith@gregsmith.com>
CC: Kevin Grittner <Kevin.Grittner@wicourts.gov>,
	pgsql-performance@postgresql.org
Subject: Re: Strange behavior: pgbench and new Linux kernels
References: <Pine.GSO.4.64.0804170230180.26917@westnet.com>
	<fd145f7d0804171009h7658d3bbqf099b5c0e9235268@mail.gmail.com>
	<Pine.LNX.4.64.0804171840180.20402@aragorn.flymine.org>
	<Pine.GSO.4.64.0804172002010.15803@westnet.com>
	<49D2466F.EE98.0025.0@wicourts.gov>
	<alpine.GSO.2.01.0904041147540.27286@westnet.com>
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On 4/4/09 9:07 AM, Greg Smith wrote:
> On Tue, 31 Mar 2009, Kevin Grittner wrote:
>
>>>>> On Thu, Apr 17, 2008 at 7:26 PM, Greg Smith wrote:
>>
>>> On this benchmark 2.6.25 is the worst kernel yet:
>>
>> I don't remember seeing a follow-up on this issue from last year.
>> Are there still any particular kernels to avoid based on this?
>
> I just discovered something really fascinating here. The problem is
> strictly limited to when you're connecting via Unix-domain sockets; use
> TCP/IP instead, and it goes away.

Have you sent this to any Linux kernel engineers?  My experience is that 
they're fairly responsive to this sort of thing.

--Josh