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charset=us-ascii Content-Disposition: inline In-Reply-To: <62e231a8f2e50c04dcadc7a0cfaa6dea5ce1ec05.1681296022.git.baolin.wang@linux.alibaba.com> X-Rspamd-Queue-Id: 82C5F160022 X-Stat-Signature: uemgreod1b4gs4pyecid7dgm7hk8ytxa X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1681298105-837005 X-HE-Meta: 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 Q1TLZAji JfXxisOdfU4/uXGM+HCHo58DNMKpfetHBddlG0zCdBOxMT2527QsH7Ol0ob19vsrjGLMKMq53Skq5Z98mnk7rLzeLbACNGhEq/atWrMM8tMrW/geofwV0xacoATIkH4yyTo5ZdtsFV/kJKUGTeJK8jFBHOalp/SpqvESkbOmgZTQALUBswMeF2YNSBOuZCt4AUFApfLgjQqBkIvVEjqibwlPzvQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed 12-04-23 18:45:31, Baolin Wang wrote: > Now the __pageblock_pfn_to_page() is used by set_zone_contiguous(), > which checks whether the given zone contains holes, and uses pfn_valid() > to check if the end pfn is valid. However pfn_valid() can not make sure > the end pfn is not a hole if the size of a pageblock is larger than the > size of a sub-mem_section, since the struct page getting by pfn_to_page() > may represent a hole or an unusable page frame, which may cause incorrect > zone contiguous is set. > > Though another user of pageblock_pfn_to_page() in compaction seems work > well now, it is better to avoid scanning or touching these offline pfns. > So like commit 2d070eab2e82 ("mm: consider zone which is not fully > populated to have holes"), we should also use pfn_to_online_page() for > the end pfn to make sure it is a valid pfn with usable page frame. > Meanwhile the pfn_valid() for end pfn can be dropped now. > > Moreover we've already used pfn_to_online_page() for start pfn to make > sure it is online and valid, so the pfn_valid() for the start pfn is > unnecessary, drop it. Is this a theoretical problem or something you have encountered on a real machine? Could you provide more details please? -- Michal Hocko SUSE Labs