From: William Yu <wyu@talisys.com>
Subject: Re: Performance problems on 4/8way Opteron (dualcore)
Date: Sun, 31 Jul 2005 14:11:58 -0700
Organization: Hub.Org Networking Services
Lines: 30
Message-ID: <dcjer1$16ov$1@news.hub.org>
References: <dcfbtl$2msc$1@news.hub.org> <BF123C5B.868%jrogers@neopolitan.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
User-Agent: Mozilla Thunderbird 1.0.2 (X11/20050317)
In-Reply-To: <BF123C5B.868%jrogers@neopolitan.com>
To: pgsql-performance@postgresql.org

A 4xDC would be far more sensitive to poor NUMA code than 2xDC so I'm 
not surprised I don't see performance issues on our 2xDC w/ < 2.6.12.


J. Andrew Rogers wrote:
> On 7/30/05 12:57 AM, "William Yu" <wyu@talisys.com> wrote:
> 
>>I haven't investigated the 2.6.12+ kernel updates yet -- I probably will
>>do our development servers first to give it a test.
> 
> 
> 
> The kernel updates make the NUMA code dual-core aware, which apparently
> makes a big difference in some cases but not in others.  It makes some
> sense, since multi-processor multi-core machines will have two different
> types of non-locality instead of just one that need to be managed.  Prior to
> the v2.6.12 patches, a dual-core dual-proc machine was viewed as a quad-proc
> machine.
> 
> The closest thing to a supported v2.6.12 kernel that I know of is FC4, which
> is not really supported in the enterprise sense of course.
> 
> 
> J. Andrew Rogers
> 
> 
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster
>