Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263310AbUAOV55 (ORCPT ); Thu, 15 Jan 2004 16:57:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263475AbUAOV54 (ORCPT ); Thu, 15 Jan 2004 16:57:56 -0500 Received: from e4.ny.us.ibm.com ([32.97.182.104]:14538 "EHLO e4.ny.us.ibm.com") by vger.kernel.org with ESMTP id S263310AbUAOV5x (ORCPT ); Thu, 15 Jan 2004 16:57:53 -0500 From: James Cleverdon Reply-To: jamesclv@us.ibm.com Organization: IBM LTC To: Zwane Mwaikambo , "Nakajima, Jun" Subject: Re: [PATCH] 2.6.1-mm2: Get irq_vector size right for generic subarch UP installer kernels Date: Thu, 15 Jan 2004 13:57:16 -0800 User-Agent: KMail/1.5 Cc: Andrew Morton , linux-kernel@vger.kernel.org, Linus Torvalds , Chris McDermott , "Martin J. Bligh" References: <7F740D512C7C1046AB53446D3720017361883D@scsmsx402.sc.intel.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200401151357.16807.jamesclv@us.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1591 Lines: 34 On Wednesday 14 January 2004 8:36 pm, Zwane Mwaikambo wrote: > On Wed, 14 Jan 2004, Nakajima, Jun wrote: > > I tend to agree. I think the confusing part is the range of the IRQs on > > that machine. Assuming that irq_vector[NR_IRQ_VECTORS = 1024] requires > > more entries, then the IRQs should take that range, because > > IO_APCI_VECTOR(irq) is just irq_vector[irq], for example. If NR_IRQS is > > still 224, how can do_IRQ() can get the correct IRQ (i.e. >= 224) ? So > > in that case, the IRQ should be smaller than 224, then irq_vector[] > > should be smaller. > > In my opinion we should be breaking after we've exceeded the maximum > external vectors we can install. This will of course mean less than > the number of RTEs. James have you actually managed to use the devices > connected to the high (over ~224) RTEs? No, I haven't exceeded the available vectors, but wli has on a large NUMA-Q box. The x440 and x445's problems are pre-reserving lots of bus numbers in the BIOS, more than one per PCI slot. They must be anticipating PCI cards with bridge chips on them. I believe that the reason for irq_vector being so large is to allow IRQ (and eventually vector) sharing. The array is to map from RTE to vector. -- James Cleverdon IBM xSeries Linux Solutions {jamesclv(Unix, preferred), cleverdj(Notes)} at us dot ibm dot comm - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/