On Tue, 2023-03-28 at 16:16 -0700, Jakub Kicinski wrote:I will run some more tests as soon as I have time for it.
On Tue, 28 Mar 2023 21:59:25 +0200 Felix Fietkau wrote:
> When dealing with few flows or an imbalance on CPU utilization, static RPS
> CPU assignment can be too inflexible. Add support for enabling threaded NAPI
> for backlog processing in order to allow the scheduler to better balance
> processing. This helps better spread the load across idle CPUs.
Can you share some numbers vs a system where RPS only spreads to the cores which are not running NAPI?
IMHO you're putting a lot of faith in the scheduler and you need to show that it actually does what you say it will do.
I have the same feeling. From your description I think some gain isDepends on the process priority, I guess.
possible if there are no other processes running except
ksoftirq/rps/threaded napi.
I guess that the above is expect average state for a small s/w router,
but if/when routing daemon/igmp proxy/local web server kicks-in you
should notice a measurable higher latency (compared to plain RPS in the
same scenario)???