Re: [PATCH v7 3/7] mm,hugetlb: Clear HPageFreed outside of the lock

[Mike Kravetz]

On 4/14/21 3:49 AM, Oscar Salvador wrote:
> On Wed, Apr 14, 2021 at 12:32:58PM +0200, Michal Hocko wrote:
>> Well, to be precise it does the very same thing with memamp struct pages
>> but that is before the initialization code you have pointed out above.
>> In this context it just poisons the allocated content which is the GB
>> page storage.
> 
> Right.
> 
>>> I checked, and when we get there in __alloc_bootmem_huge_page, page->private is
>>> still zeroed, so I guess it should be safe to assume that we do not really need
>>> to clear the flag in __prep_new_huge_page() routine?
>>
>> It would be quite nasty if the struct pages content would be undefined.
>> Maybe that is possible but then I would rather stick the initialization
>> into __alloc_bootmem_huge_page.
> 
> Yes, but I do not think that is really possible unless I missed something.
> Let us see what Mike thinks of it, if there are no objections, we can
> get rid of the clearing flag right there.
>  

Thanks for crawling through that code Oscar!

I do not think you missed anything.  Let's just get rid of the flag
clearing.
-- 
Mike Kravetz