Re: [RFC v2] net/core: add optional threading for rps backlog processing

[Eric Dumazet]

On Fri, Feb 17, 2023 at 1:35 PM Felix Fietkau <nbd@xxxxxxxx> wrote:
>
> On 17.02.23 13:23, Eric Dumazet wrote:
> > On Fri, Feb 17, 2023 at 11:06 AM Felix Fietkau <nbd@xxxxxxxx> 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 RPS backlog processing in order to allow the scheduler to better balance
> >> processing. This helps better spread the load across idle CPUs.
> >>
> >> Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
> >> ---
> >>
> >> RFC v2:
> >>  - fix rebase error in rps locking
> >
> > Why only deal with RPS ?
> >
> > It seems you propose the sofnet_data backlog be processed by a thread,
> > instead than from softirq ?
> Right. I originally wanted to mainly improve RPS, but my patch does
> cover backlog in general. I will update the description in the next
> version. Does the approach in general make sense to you?
>

I do not know, this seems to lack some (perf) numbers, and
descriptions of added max latencies and stuff like that :)