From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtpauth.hypersurf.com (smtpauth.hypersurf.com [209.237.0.8]) by ozlabs.org (Postfix) with ESMTP id 3A00CDDE11 for ; Mon, 27 Oct 2008 12:33:21 +1100 (EST) Message-ID: <490527CF.80908@hypersurf.com> Date: Sun, 26 Oct 2008 18:30:39 -0800 From: Kevin Diggs MIME-Version: 1.0 To: benh@kernel.crashing.org Subject: Re: [PATCH] genirq: Set initial default irq affinity to just CPU0 References: <1224863858-7933-1-git-send-email-galak@kernel.crashing.org> <20081024.161813.193686281.davem@davemloft.net> <1224970389.7654.473.camel@pasglop> <4903A37A.50607@hypersurf.com> <1225003723.7654.490.camel@pasglop> In-Reply-To: <1225003723.7654.490.camel@pasglop> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Benjamin Herrenschmidt wrote: >>What does this all mean to my GigE (dual 1.1 GHz 7455s)? Is this >>thing supposed to be able to spread irq between its cpus? > > > Depends on the interrupt controller. I don't know that machine > but for example the Apple Dual G5's use an MPIC that can spread > based on an internal HW round robin scheme. This isn't always > the best idea tho for cache reasons... depends if an at what level > your caches are shared between CPUs. > > Ben. > Sorry. I thought GigE was a common name for the machine. It is a dual 450 MHz G4 powermac with a gigabit ethernet and AGP. It now has a PowerLogix dual 1.1 GHz 7455 in it. I think the L3 caches are seperate? Not sure about the original cpu card. Can the OS tell? The reason I asked is that I seem to remember a config option that would restrict the irqs to cpu 0? Help suggested it was needed for certain PowerMacs. Didn't provide any help as to which ones. My GigE currently spreads them between the two. I have not noticed any additional holes in the space time contiuum. kevin