Re: [PATCH v1 5/5] mm/memory_hotplug: print only with DEBUG_VM in online/offline_pages()

[Wei Yang]

On Mon, Aug 20, 2018 at 11:57:04AM +0200, David Hildenbrand wrote:
>On 19.08.2018 14:34, Wei Yang wrote:
>> On Fri, Aug 17, 2018 at 10:18:53AM +0200, Oscar Salvador wrote:
>>>>  failed_addition:
>>>> +#ifdef CONFIG_DEBUG_VM
>>>>  	pr_debug("online_pages [mem %#010llx-%#010llx] failed\n",
>>>>  		 (unsigned long long) pfn << PAGE_SHIFT,
>>>>  		 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1);
>>>> +#endif
>>>
>>> I have never been sure about this.
>>> IMO, if I fail to online pages, I want to know I failed.
>>> I think that pr_err would be better than pr_debug and without CONFIG_DEBUG_VM.
>>>
>>> But at least, if not, envolve it with a CONFIG_DEBUG_VM, but change pr_debug to pr_info.
>>>
>> 
>> I don't have a clear rule about these debug macro neither.
>> 
>> While when you look at the page related logs in calculate_node_totalpages(),
>> it is KERNEL_DEBUG level and without any config macro.
>> 
>> Maybe we should leave them at the same state?
>
>I guess we can do that for the to debug messages.
>
>When offlining memory right now:
>
>:/# echo 0 > /sys/devices/system/memory/memory9/online
>[   24.476207] Offlined Pages 32768
>[   24.477200] remove from free list 48000 1024 50000
>[   24.477896] remove from free list 48400 1024 50000
>[   24.478584] remove from free list 48800 1024 50000
>[   24.479454] remove from free list 48c00 1024 50000
>[   24.480192] remove from free list 49000 1024 50000
>[   24.480957] remove from free list 49400 1024 50000
>[   24.481752] remove from free list 49800 1024 50000
>[   24.482578] remove from free list 49c00 1024 50000
>[   24.483302] remove from free list 4a000 1024 50000
>[   24.484300] remove from free list 4a400 1024 50000
>[   24.484902] remove from free list 4a800 1024 50000
>[   24.485462] remove from free list 4ac00 1024 50000
>[   24.486381] remove from free list 4b000 1024 50000
>[   24.487108] remove from free list 4b400 1024 50000
>[   24.487842] remove from free list 4b800 1024 50000
>[   24.488610] remove from free list 4bc00 1024 50000
>[   24.489548] remove from free list 4c000 1024 50000
>[   24.490392] remove from free list 4c400 1024 50000
>[   24.491224] remove from free list 4c800 1024 50000
>...
>
>While "remove from free list" is pr_info under CONFIG_DEBUG_VM,
>"Offlined Pages ..." is pr_info without CONFIG_DEBUG_VM.

Hmm... yes, don't see the logic between them.

>
>-- 
>
>Thanks,
>
>David / dhildenb

-- 
Wei Yang
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