x86/irq: optimize nr_irqs (f1ee5548) · Commits · 戴 / test

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 <yinghai@kernel.org> Signed-off-by:

Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/io_apic.c

+11 −5

Original line number	Diff line number	Diff line
		@@ -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;

Admin message