Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S275046AbTHLFxC (ORCPT ); Tue, 12 Aug 2003 01:53:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S275050AbTHLFxC (ORCPT ); Tue, 12 Aug 2003 01:53:02 -0400 Received: from mail.kroah.org ([65.200.24.183]:56519 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S275046AbTHLFxA (ORCPT ); Tue, 12 Aug 2003 01:53:00 -0400 Date: Mon, 11 Aug 2003 22:53:08 -0700 From: Greg KH To: Zwane Mwaikambo Cc: long , jun.nakajima@intel.com, linux-kernel@vger.kernel.org, pcihpd-discuss@lists.sourceforge.net, tom.l.nguyen@intel.com Subject: Re: Updated MSI Patches Message-ID: <20030812055308.GA1912@kroah.com> References: <200308112051.h7BKp9ZU003007@snoqualmie.dp.intel.com> <20030811211654.GA18578@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1316 Lines: 30 On Mon, Aug 11, 2003 at 09:41:30PM -0400, Zwane Mwaikambo wrote: > > > I hope there may be a way to determine the number of vectors supported > > > by CPU during the run-time. I look at the file ../include/asm-i386/mach- > > > default/irq_vectors.h, the maximum of vectors (256) is already well > > > commented. > > > > Yeah, but that's in reference to APIC interrupt sources, right? Does > > that correspond to these "vectors" too? If so, why not just use the > > existing NR_IRQS value instead of creating your own? > > There isn't a 1:1 relationship between NR_IRQS and NR_VECTORS we really > shouldn't mix them together. NR_IRQS can be much higher than 256 whilst > on i386 we're fixed to 256 vectors due to that being the Interrupt > Descriptor Table capacity. It is still possible to service more interrupt > lines than 256 on SMP however by making IDTs per 'interrupt servicing > node' Ah, so for processors other than i386, NR_VECTORS can be bigger? I think a nice description is still needed for this value for just this reason :) thanks, greg k-h - 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/