From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753512AbZBHJpT (ORCPT ); Sun, 8 Feb 2009 04:45:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752773AbZBHJpE (ORCPT ); Sun, 8 Feb 2009 04:45:04 -0500 Received: from hera.kernel.org ([140.211.167.34]:44540 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752698AbZBHJpD (ORCPT ); Sun, 8 Feb 2009 04:45:03 -0500 Message-ID: <498EA964.2070902@kernel.org> Date: Sun, 08 Feb 2009 01:44:04 -0800 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Andrew Morton CC: "linux-kernel@vger.kernel.org" Subject: [PATCH] x86/irq: optimizing nr_irqs -v2 References: <498CCEDB.8050708@kernel.org> <498CCF28.3050207@kernel.org> In-Reply-To: <498CCF28.3050207@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Impact: more depend on cards to be used depend on nr_irq_gsi more, and have a ratio for MSI v2: make nr_irqs shoule less than NR_VECTORS * nr_cpu_ids aka if only one cpu, we only can support nr_irqs = NR_VECTORS Signed-off-by: Yinghai Lu --- arch/x86/kernel/io_apic.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) Index: linux-2.6/arch/x86/kernel/io_apic.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/io_apic.c +++ linux-2.6/arch/x86/kernel/io_apic.c @@ -3482,9 +3482,9 @@ int arch_setup_msi_irqs(struct pci_dev * sub_handle = 0; list_for_each_entry(msidesc, &dev->msi_list, list) { irq = create_irq_nr(irq_want); - irq_want++; if (irq == 0) return -1; + irq_want = irq + 1; #ifdef CONFIG_INTR_REMAP if (!intr_remapping_enabled) goto no_ir; @@ -3838,11 +3838,17 @@ int __init arch_probe_nr_irqs(void) { int nr; - nr = ((8 * nr_cpu_ids) > (32 * nr_ioapics) ? - (NR_VECTORS + (8 * nr_cpu_ids)) : - (NR_VECTORS + (32 * nr_ioapics))); + if (nr_irqs > (NR_VECTORS * nr_cpu_ids)) + nr_irqs = NR_VECTORS * nr_cpu_ids; - if (nr < nr_irqs && nr > nr_irqs_gsi) + nr = nr_irqs_gsi + 8 * nr_cpu_ids; +#if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ) + /* + * for MSI and HT dyn irq + */ + nr += nr_irqs_gsi * 16; +#endif + if (nr < nr_irqs) nr_irqs = nr; return 0;