Re: [PATCH v8 3/7] crash: add generic infrastructure for crash hotplug support

David Hildenbrand
2022-06-15T09:53:50Z

On 01.06.22 00:25, Eric DeVolder wrote:
>
>
> On 5/31/22 08:15, David Hildenbrand wrote:
>> On 12.05.22 18:10, Eric DeVolder wrote:
>>> David,
>>> Great questions! See inline responses below.
>>> eric
>>
>> Sorry for the late reply, travel and vacation ...
> No problem, greatly appreciate the feedback!
> eric
>
>>
>>>>
>>>>> +
>>>>> +#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_MEMORY_HOTPLUG)
>>>>> +void __weak arch_crash_handle_hotplug_event(struct kimage *image,
>>>>> + unsigned int hp_action, unsigned int cpu)
>>>>> +{
>>>>> + WARN(1, "crash hotplug handler not implemented");
>>>>
>>>>
>>>> Won't that trigger on any arch that has CONFIG_HOTPLUG_CPU and CONFIG_MEMORY_HOTPLUG?
>>>> I mean, you only implement it for x86 later in this series. Or what else stops this WARN from
>>>> triggering?
>>>>
>>> You're correct. What about: printk_once(KERN_DEBUG "...") ?
>>
>> Why even bother about printing anything? If the feature is not
>> supported, there should be some way for user space to figure out that it
>> sill has to reload on hot(un)plug manually, no?
>
> I've changed this to WARN_ONCE(). If that isn't agreeable, I'll remove it.

Please don't use WARN* on expected error paths.

--
Thanks,

David / dhildenb