From f1ee5548a6507d2b4293635c61ddbf12e2c00e94 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Sun, 8 Feb 2009 16:18:03 -0800 Subject: [PATCH] x86/irq: optimize nr_irqs Impact: make nr_irqs depend more on cards used in a system depend on nr_irq_gsi more, and have a ratio for MSI. v2: make nr_irqs 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 Signed-off-by: Ingo Molnar --- arch/x86/kernel/io_apic.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c index 9578d33f20a..43f95d7b13a 100644 --- a/arch/x86/kernel/io_apic.c +++ b/arch/x86/kernel/io_apic.c @@ -3479,9 +3479,9 @@ int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) 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; @@ -3825,11 +3825,17 @@ 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; -- 2.46.0