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Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH 2/4] mm/huge_memory: move to next folio after folio_split() succeeds. 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>>>> } else { >>>> - struct page *split_at = folio_page(folio, >>>> - in_folio_offset); >>>> - if (!folio_split(folio, target_order, split_at, NULL)) >>>> + struct page *split_at = >>>> + folio_page(folio, in_folio_offset); >>>> + if (!folio_split(folio, target_order, split_at, NULL)) { >>>> split++; >>>> + addr += PAGE_SIZE * nr_pages; >>>> + } >>> >>> Are we sure addr points to the folio start? >> >> David pointed it out. Will use addr += PAGE_SIZE * (nr_pages - 1). >> > > No, let me be more clear. I am talking about the addr in next iteration. I am > talking about the addr in this round. > > For an addr in the middle of 2M, we still could get the large folio if my > understanding is correct. Then (addr + whole folio size) seems wrong. > > addr > | > v > +-------------------+ > | | > +-------------------+ > > Not sure this would be the case. Got it. addr should be aligned up to PAGE_SIZE * nr_pages to get to the next folio. Thanks. -- Best Regards, Yan, Zi