On 2017/12/4 20:35, Michal Hocko wrote: > On Mon 04-12-17 20:23:49, zhong jiang wrote: >> 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@xxxxxxxxxxxxxxxxxxxx wrote: >>>>>>> From: zhong jiang <zhongjiang@xxxxxxxxxx> >>>>>>> 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@xxxxxxxxxx >>>>>>> Signed-off-by: zhong jiang <zhongjiang@xxxxxxxxxx> >>>>>>> Cc: Michal Hocko <mhocko@xxxxxxxxxx> >>>>>>> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >>>>>> The author never responded and Michal Hocko basically NAKed it in >>>>>> https://lkml.kernel.org/r/<20160812130727.GI3639@xxxxxxxxxxxxxx> >>>>>> 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. :-) > git grep says some in page_ext.c, memory_hotplug.c and few in the arch > code. I belive we really want to describe and document the distinction > between the two constants and explain when to use which one. > yes, limited by my knowledge and english. Maybe Vlastimil can address it in detail. Thanks zhongjiang -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
