[PATCH] x86: increase NR_IRQS and nr_irqs

[Yinghai Lu]

have a system with lots of igb and ixgbe, when iov/vf are enabled for
them, we hit the limit of 3064.

so try to increase NR_IRQS and nr_irqs to about 8000 and 6000.
for that system.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

---
 arch/x86/include/asm/irq_vectors.h |   12 ++++++------
 arch/x86/kernel/apic/io_apic.c     |    2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)

Index: linux-2.6/arch/x86/include/asm/irq_vectors.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/irq_vectors.h
+++ linux-2.6/arch/x86/include/asm/irq_vectors.h
@@ -154,21 +154,21 @@ static inline int invalid_vm86_irq(int i
 
 #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
Index: linux-2.6/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6/arch/x86/kernel/apic/io_apic.c
@@ -3840,7 +3840,7 @@ int __init arch_probe_nr_irqs(void)
 	/*
 	 * for MSI and HT dyn irq
 	 */
-	nr += nr_irqs_gsi * 16;
+	nr += nr_irqs_gsi * 48;
 #endif
 	if (nr < nr_irqs)
 		nr_irqs = nr;
--
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