linux 雙核問題

邏輯CPU個數

cat /proc/cpuinfo | grep "processor" | wc -l

cat /proc/interrupts

           CPU0       CPU1      
  0:        168          0   IO-APIC-edge      timer
  1:         79          0   IO-APIC-edge      i8042
  4:          2          0   IO-APIC-edge   
  8:          1          0   IO-APIC-edge      rtc0
  9:          0          0   IO-APIC-fasteoi   acpi
 10:     302080          0   IO-APIC-fasteoi   virtio0, eth0
 11:        314          0   IO-APIC-fasteoi   uhci_hcd:usb1, sym53c8xx, Intel 82801AA-ICH
 12:        667          0   IO-APIC-edge      i8042
 14:      35182          0   IO-APIC-edge      ata_piix
 15:       3225          0   IO-APIC-edge      ata_piix
NMI:          0          0   Non-maskable interrupts
LOC:    2361875    2546808   Local timer interrupts
SPU:          0          0   Spurious interrupts
PMI:          0          0   Performance monitoring interrupts
IWI:          0          0   IRQ work interrupts
RES:      23414      23637   Rescheduling interrupts
CAL:         48      21032   Function call interrupts
TLB:       2334       1823   TLB shootdowns
TRM:          0          0   Thermal event interrupts
THR:          0          0   Threshold APIC interrupts
MCE:          0          0   Machine check exceptions
MCP:          0          0   Machine check polls

可以看到

10: 302080 .................eth0

利用

cat /proc/irq/irq編號/smp_affinity

cat /proc/irq/10/smp_affinity

秀3表示用CPU0和CPU1 (2^0+2^1)

Binary       Hex
CPU 0    0001         1
CPU 1    0010         2
CPU 2    0100         4
CPU 3    1000         8

利用

echo 3 > /proc/irq/10/smp_affinity 
有些網卡在開機啟動時要加上pci=nomsi的參數

也可裝上irqbalance
#yum install irqbalance

chkconfig--level 345 irqbalance on   　//開機啟動。
serviceirqbalance start