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. -- Michal Hocko SUSE Labs -- 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>
