Re: [patch 13/15] mm/page_owner: align with pageblock_nr pages

[zhong jiang <zhongjiang@huawei.com>]

On 2017/12/4 20:01, Michal Hocko wrote:
> On Mon 04-12-17 19:51:12, zhong jiang wrote:
>> On 2017/12/2 1:15, Michal Hocko wrote:
>>> On Fri 01-12-17 17:58:28, Vlastimil Babka wrote:
>>>> On 11/30/2017 11:15 PM, akpm@linux-foundation.org wrote:
>>>>> From: zhong jiang <zhongjiang@huawei.com>
>>>>> Subject: mm/page_owner: align with pageblock_nr pages
>>>>>
>>>>> When pfn_valid(pfn) returns false, pfn should be aligned with
>>>>> pageblock_nr_pages other than MAX_ORDER_NR_PAGES in init_pages_in_zone,
>>>>> because the skipped 2M may be valid pfn, as a result, early allocated
>>>>> count will not be accurate.
>>>>>
>>>>> Link: http://lkml.kernel.org/r/1468938136-24228-1-git-send-email-zhongjiang@huawei.com
>>>>> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
>>>>> Cc: Michal Hocko <mhocko@kernel.org>
>>>>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>>>> The author never responded and Michal Hocko basically NAKed it in
>>>> https://lkml.kernel.org/r/<20160812130727.GI3639@dhcp22.suse.cz>
>>>> I think we should drop it.
>>> Or extend the changelog to actually describe what kind of problem it
>>> fixes and do an additional step to unigy
>>> MAX_ORDER_NR_PAGES/pageblock_nr_pages
>>>  
>>   Hi, Michal
>>    
>>         IIRC,  I had explained the reason for patch.  if it not. I am so sorry for that.
>>     
>>         when we select MAX_ORDER_NR_PAGES,   the second 2M will be skiped.
>>        it maybe result in normal pages leak.
>>
>>         meanwhile.  as you had said.  it make the code consistent.  why do not we do it.
>>    
>>         I think it is reasonable to upstream the patch.  maybe I should rewrite the changelog
>>        and repost it.
>>
>>     Michal,  Do you think ?
> Yes, rewrite the patch changelog and make it _clear_ what it fixes and
> under _what_ conditions. There are also other places using
> MAX_ORDER_NR_PAGES rathern than pageblock_nr_pages. Do they need to be
> updated as well?
 in the lastest kernel.  according to correspond context,   I  can not find the candidate. :-)

  Thanks
  zhongjiang

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