Re: [PATCH v2] mm/page_alloc: fix watchdog soft lockups during set_zone_contiguous()

[David Hildenbrand]

On 20.04.20 09:34, Michal Hocko wrote:
> On Fri 17-04-20 15:12:47, Andrew Morton wrote:
>> On Thu, 16 Apr 2020 09:34:17 +0200 David Hildenbrand <david@xxxxxxxxxx> wrote:
>>
>>> Without CONFIG_PREEMPT, it can happen that we get soft lockups detected,
>>> e.g., while booting up.
>>>
>>> ...
>>>
>>> --- a/mm/page_alloc.c
>>> +++ b/mm/page_alloc.c
>>> @@ -1607,6 +1607,7 @@ void set_zone_contiguous(struct zone *zone)
>>>  		if (!__pageblock_pfn_to_page(block_start_pfn,
>>>  					     block_end_pfn, zone))
>>>  			return;
>>> +		cond_resched();
>>>  	}
>>>  
>>>  	/* We confirm that there is no hole */
>>
>> I added cc:stable to this one.  Please let me know if that wasn't a
>> good idea.
> 
> Really large memory setups tend to run on distribution kernels so
> backporting to old kernels doesn't really harm.
> 

Yeah, shouldn't hurt.

-- 
Thanks,

David / dhildenb