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Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Kevin Brodsky Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260924-fix_split-v8-0-cba7359d882a@arm.com> <20260924-fix_split-v8-3-cba7359d882a@arm.com> Content-Language: en-US From: Sarthak Sharma In-Reply-To: <20260924-fix_split-v8-3-cba7359d882a@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 4DB5B40007 X-Stat-Signature: ab57apptwt3uixeu9xp4opzfezttnogz X-Rspam-User: X-HE-Tag: 1790340902-827341 X-HE-Meta: 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 MYlbb392 GaCZy5g7ZHuxmFPCbb25ZD4yxO8MzcQuPSJTcZoUxewT51lWBiizq6O4cKXT+CS15bpptSapYFvM9yG8Yg944Bt7kP0crANp2NxGyWfSWTTn7x84lOHfSryyeMNQWnwOX0Ekfzl1L/LOX0FT3ssyINUA/K/qIu/OyOJcXKRTco65Sla/SNlgRCRyS4IwX7EweCTXp0npTdd2De23iYVK/zfEKTHkCxaNHseaO4sDbgf4Tf2utwHRXrHXYWslPibNWf3cqnmrPUYHYaM6mvOZw8UiV+ZN3KvO5L3NfKNV0Twg3kUdwQNq9N8gxvpwP/jOUslyUeeWLEkWivxFEuL6x8lgfVQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/25/26 12:41 AM, Yeoreum Yun wrote: > check_large_folios() only checks for large folios without distinguishing > between anonymous and file-backed huge pages. > > To add huge page type checking, integrate the huge page checks into > __check_huge(): > > 1. If hpage_size == pmd_pagesize, check PAGE_IS_HUGE instead of using > check_large_folios(), since only the mapping type matters. This > identifies PMD-mapped huge pages. > > 2. Otherwise, use check_large_folios() to detect large folios. This > covers mTHP cases. > > 3. Check the folio flags according to the huge page type. > > Suggested-by: David Hildenbrand (Arm) > Suggested-by: Zi Yan > Signed-off-by: Yeoreum Yun > --- Looks good to me, some nits below. Reviewed-by: Sarthak Sharma [...] > -static bool __check_pmd_huge(void *addr, size_t len, int nr_hpages, > - uint64_t hpage_size, enum check_huge_type type) > +static bool __check_huge(void *addr, size_t len, int nr_hpages, > + uint64_t hpage_size, enum check_huge_type type) > { > - int pagemap_fd; > + bool ret = false; > + int pagemap_fd, kpageflags_fd; > int nr_pmd_mappings = 0; > + uint64_t pmd_pagesize, scan_mapping_size; > uint64_t categories; > + unsigned long pfn; > + bool check_pmd_mapping, allow_nonpresent; > char *start = addr; > char *end = start + len; > > + pmd_pagesize = read_pmd_pagesize(); > + if (!pmd_pagesize) > + ksft_exit_fail_msg("reading PMD pagesize failed\n"); > + > + check_pmd_mapping = hpage_size == pmd_pagesize; > + scan_mapping_size = (nr_hpages > 0) ? hpage_size : psize(); > + /* Some mTHP tests check a partially populated PMD-sized range. */ > + allow_nonpresent = (uint64_t)nr_hpages * hpage_size < len; > + > pagemap_fd = open(PAGEMAP_PATH, O_RDONLY); > if (pagemap_fd < 0) > ksft_exit_fail_msg("open pagemap fail\n"); > > - for (; start < end; start += hpage_size) { > + kpageflags_fd = open(KPAGEFLAGS_PATH, O_RDONLY); > + if (kpageflags_fd < 0) > + ksft_exit_fail_msg("open kpageflags fail\n"); Again, can we change it to ksft_exit_fail_perror()? > + > + if (!check_pmd_mapping && > + !check_large_folios(pagemap_fd, kpageflags_fd, > + addr, len, nr_hpages, hpage_size)) > + goto out; > + > + for (; start < end; start += scan_mapping_size) { > categories = pagemap_scan_get_categories(pagemap_fd, start); > - if (!(categories & PAGE_IS_HUGE)) > - continue; > - if (check_huge_type(categories, type)) > + pfn = pagemap_get_pfn(pagemap_fd, start); > + if (pfn == -1UL) { > + if (!allow_nonpresent) > + goto out; > + else Nit: We can skip this else here. > + continue; > + } > + if (check_pmd_mapping && (categories & PAGE_IS_HUGE)) > nr_pmd_mappings++; > + if (!check_huge_type(categories, type)) > + goto out; > } > - close(pagemap_fd); > > - return nr_hpages == nr_pmd_mappings; > + if (check_pmd_mapping && (nr_pmd_mappings != nr_hpages)) > + goto out; > + ret = true; > + > +out: > + close(pagemap_fd); > + close(kpageflags_fd); > + return ret; > }