Re: [PATCH] lib/smp_processor_id: Don't warn if there is only one CPU

[Steven Rostedt]

On Thu, 12 Nov 2026 09:13:48 +0100
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> num_possible_cpus() is what I was thinking of. Notably, there is no
> requirement that the CPU bitmap is dense. You can have nr_cpu_ids at 256
> and use 255 for your boot CPU. It would be completely daft to do so, but
> it is still valid.

Hmm, I was under the impression that there would always be a CPU 0.

Is it possible to boot with a non zero CPU setup?

-- Steve