From 9959c888a38b0f25b0e81a480f537d6489348442 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 28 Dec 2009 21:08:29 -0800 Subject: x86: Increase NR_IRQS and nr_irqs I have a system with lots of igb and ixgbe, when iov/vf are enabled for them, we hit the limit of 3064. when system has 20 pcie installed, and one card has 2 functions, and one function needs 64 msi-x, may need 20 * 2 * 64 = 2560 for msi-x but if iov and vf are enabled may need 20 * 2 * 64 * 3 = 7680 for msi-x assume system with 5 ioapic, nr_irqs_gsi will be 120. NR_CPUS = 512, and nr_cpu_ids = 128 will have NR_IRQS = 256 + 512 * 64 = 33024 will have nr_irqs = 120 + 8 * 128 + 120 * 64 = 8824 When SPARSE_IRQ is not set, there is no increase with kernel data size. when NR_CPUS=128, and SPARSE_IRQ is set: text data bss dec hex filename 21837444 4216564 12480736 38534744 24bfe58 vmlinux.before 21837442 4216580 12480736 38534758 24bfe66 vmlinux.after when NR_CPUS=4096, and SPARSE_IRQ is set text data bss dec hex filename 21878619 5610244 13415392 40904255 270263f vmlinux.before 21878617 5610244 13415392 40904253 270263d vmlinux.after Signed-off-by: Yinghai Lu Cc: Linus Torvalds Cc: Andrew Morton LKML-Reference: <4B398ECD.1080506@kernel.org> Signed-off-by: Ingo Molnar --- arch/x86/include/asm/irq_vectors.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h index 4611f085cd4..3ab43df089c 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -154,21 +154,21 @@ static inline int invalid_vm86_irq(int irq) #define NR_IRQS_LEGACY 16 -#define CPU_VECTOR_LIMIT ( 8 * NR_CPUS ) #define IO_APIC_VECTOR_LIMIT ( 32 * MAX_IO_APICS ) #ifdef CONFIG_X86_IO_APIC # ifdef CONFIG_SPARSE_IRQ +# define CPU_VECTOR_LIMIT (64 * NR_CPUS) # define NR_IRQS \ (CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ? \ (NR_VECTORS + CPU_VECTOR_LIMIT) : \ (NR_VECTORS + IO_APIC_VECTOR_LIMIT)) # else -# if NR_CPUS < MAX_IO_APICS -# define NR_IRQS (NR_VECTORS + 4*CPU_VECTOR_LIMIT) -# else -# define NR_IRQS (NR_VECTORS + IO_APIC_VECTOR_LIMIT) -# endif +# define CPU_VECTOR_LIMIT (32 * NR_CPUS) +# define NR_IRQS \ + (CPU_VECTOR_LIMIT < IO_APIC_VECTOR_LIMIT ? \ + (NR_VECTORS + CPU_VECTOR_LIMIT) : \ + (NR_VECTORS + IO_APIC_VECTOR_LIMIT)) # endif #else /* !CONFIG_X86_IO_APIC: */ # define NR_IRQS NR_IRQS_LEGACY -- cgit v1.2.3