Re: [Question] ixgbe：Mechanism of RSS

[Edward Cree]

On 02/01/2025 11:23, Haifeng Xu wrote:
> We want to make full use of cpu resources to receive packets. So
> we enable 63 rx queues. But we found the rate of interrupt growth
> on cpu 0~15 is faster than other cpus(almost twice).
...
> I am confused that why ixgbe NIC can dispatch the packets
> to the rx queues that not specified in RSS configuration.

Hypothesis: it isn't doing so, RX is only happening on cpus (and
 queues) 0-15, but the other CPUs are still sending traffic and
 thus getting TX completion interrupts from their TX queues.
`ethtool -S` output has per-queue traffic stats which should
 confirm this.

(But Eric is right that if you _want_ RX to use every CPU you
 should just change the indirection table.)