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

[Pasha Tatashin]

On 8/20/18 6:46 AM, David Hildenbrand wrote:
> On 16.08.2018 12:06, David Hildenbrand wrote:
>> Let's try to minimze the noise.
>>
>> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
>> ---
>>  mm/memory_hotplug.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>> index bbbd16f9d877..6fec2dc6a73d 100644
>> --- a/mm/memory_hotplug.c
>> +++ b/mm/memory_hotplug.c
>> @@ -966,9 +966,11 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
>>  	return 0;
>>  
>>  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
>>  	memory_notify(MEM_CANCEL_ONLINE, &arg);
>>  	return ret;
>>  }
>> @@ -1660,7 +1662,9 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
>>  	offlined_pages = check_pages_isolated(start_pfn, end_pfn);
>>  	if (offlined_pages < 0)
>>  		goto repeat;
>> +#ifdef CONFIG_DEBUG_VM
>>  	pr_info("Offlined Pages %ld\n", offlined_pages);
>> +#endif
>>  	/* Ok, all of our target is isolated.
>>  	   We cannot do rollback at this point. */
>>  	offline_isolated_pages(start_pfn, end_pfn);
>> @@ -1695,9 +1699,11 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
>>  	return 0;
>>  
>>  failed_removal:
>> +#ifdef CONFIG_DEBUG_VM
>>  	pr_debug("memory offlining [mem %#010llx-%#010llx] failed\n",
>>  		 (unsigned long long) start_pfn << PAGE_SHIFT,
>>  		 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
>> +#endif
>>  	memory_notify(MEM_CANCEL_OFFLINE, &arg);
>>  	/* pushback to free area */
>>  	undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
>>
> 
> I'll drop this patch for now, maybe the error messages are actually
> useful when debugging a crashdump of a system without CONFIG_DEBUG_VM.
> 

Yes, please drop it, no reason to reduce amount of these messages. They
are useful.

Thank you,
Pavel