I made some testing with streaming and see while routing between lan and wan/pppoe interrupts counting up only on cpu0. It stops from time to time.i have not much cpu usage in top,but it seems that interrupts causing this
Afair there was a way ro change cpu or maybe use all cpus…but don’t remember how. Afaik it was called affinity,but found only the crypto driver thread…
$ cat /proc/interrupts | grep eth 240: 147961822 0 0 0 MT_SYSIRQ 199 Level 1b100000.ethernet 241: 136396797 0 0 0 MT_SYSIRQ 198 Level 1b100000.ethernet
so only first cpu is used…some more interrupts operating only on cpu0. i found no dropping or similar on networking interfaces i use for this (eth0, lan0 and wan), vlan and pppoe had no statictics in ethtool
i tried moving irq to different CPU (counting not clear)
echo 2 > /proc/irq/240/smp_affinity #2 moves to cpu1 echo 4 > /proc/irq/241/smp_affinity #4 moves to cpu2 [14:22] root@bpi-r2-e:~ (349)# cat /proc/interrupts | grep eth 240: 147967496 1210 0 0 MT_SYSIRQ 199 Level 1b100000.ethernet 241: 136403870 0 728 0 MT_SYSIRQ 198 Level 1b100000.ethernet
after ~1 minute i see these (~1000 interupts /min)…isn’t this much??
i guess the interrupts are caused by NAT…my structure is wan + vlan + pppoe with NAT => routed to lan0 through iptables (which may also cause CPU-load/interrupts)