Srikar Dronamraju <sri...@linux.vnet.ibm.com> writes:
>>
>> I think just WARN_ON(cpu_online(fcpu)) would be satisfactory. In my
>> experience, the downstream effects of violating this condition are
>> varied and quite difficult to debug. Seems only appropriate to emit a
>> warning and stack trace before the OS inevitably becomes unstable.
>
> I still have to try but wouldn't this be a problem for the boot-cpu?
> I mean boot-cpu would be marked online while it tries to do numa_setup_cpu.
> No?
This is what I mean:
+ if (fcpu != lcpu) {
+ WARN_ON(cpu_online(fcpu));
+ map_cpu_to_node(fcpu, nid);
+ }
I.e. if we're modifying the mapping for a remote cpu, warn if it's
online.
I don't think this would warn on the boot cpu -- I would expect fcpu and
lcpu to be the same and this branch would not be taken.
