Re: [PATCH 3/5] x86/smpboot: Make the check code more clear in prefill_possible_map()

From: Peter Zijlstra
Date: Tue Mar 20 2018 - 08:39:36 EST


On Tue, Mar 20, 2018 at 07:04:30PM +0800, Dou Liyang wrote:
> case 1: no | no | no | --> min (setup_possible_cpus, nr_cpu_ids, setup_max_cpus)
> case 2: no | no | yes| --> min (setup_possible_cpus, nr_cpu_ids)
> case 3: no | yes | no | --> 1
> case 4: no | yes | yes| --> 1
> case 5: yes | no | no | --> min (num_processors, nr_cpu_ids, setup_max_cpus)
> case 6: yes | no | yes| --> min (num_processors + disabled_cpus, nr_cpu_ids)
> case 7: yes | yes | no | --> 1
> case 8: yes | yes | yes| --> 1

The case number is off by one ;-)