Hello CentOS !
Iam trying to configure a Dual Core 1.6Ghz AMD E-350 machine to be able NIC (eth0) interrupts the most efficient way possible so that I can be able to handle the large number of random source packets per second. Currently running CentOS 6.4 2.6.32-358.6.2.el6.x86_64, i made some load testing with a random sourced syn flood to the NIC of this machine and found out according to top all the CPU interrupts are being sent to CPU0, thus saturating it and keeping the second core 100% idle because of this the amount of PPS handled is low (50k /sec). So.. below the output of /proc/interrupts, and also the output of the SMP affinity file which already contains “3” which I expect it tells the kernel to load balance the interrupts between the two cores and its not happening.
a.) Could anyody please help me with a solution so that iam able to balance equally the interrupts on both cores?
b.) Is there anyway to actually assign more interrupts to this IRQ (25)
or is that something that the kernel discretly takes care of?
[root@node2 ~]# cat /proc/irq/25/smp_affinity
Btw I also tried setting this value to “2” and “1” to get to choose which core it handles, and that did work but again the problem is I can only use one core at a time and not balance!
[root@node2 ~]# cat /proc/interrupts
0: 229 9838 IO-APIC-edge timer
1: 0 2 IO-APIC-edge i8042
8: 0 1 IO-APIC-edge rtc0
9: 0 0 IO-APIC-fasteoi acpi
12: 0 4 IO-APIC-edge i8042
14: 0 0 IO-APIC-edge pata_atiixp
15: 0 0 IO-APIC-edge pata_atiixp
16: 4 650 IO-APIC-fasteoi snd_hda_intel
17: 0 0 IO-APIC-fasteoi ehci_hcd:usb1, ehci_hcd:usb2, ehc i_hcd:usb3
18: 0 4 IO-APIC-fasteoi ohci_hcd:usb4, ohci_hcd:usb5, ohc i_hcd:usb6, ohci_hcd:usb7
19: 7 2754 IO-APIC-fasteoi ahci
24: 0 31 PCI-MSI-edge snd_hda_intel
25: 1 876343 PCI-MSI-edge eth0