The helper gathers an folio order statistics of folios within a virtual address range and checks it against a given order list. It aims to provide a more precise folio order check instead of just checking the existence of PMD folios.
Signed-off-by: Zi Yan ziy@nvidia.com --- tools/testing/selftests/mm/vm_util.c | 139 +++++++++++++++++++++++++++ tools/testing/selftests/mm/vm_util.h | 2 + 2 files changed, 141 insertions(+)
diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c index 9dafa7669ef9..373621145b2a 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -17,6 +17,12 @@ #define STATUS_FILE_PATH "/proc/self/status" #define MAX_LINE_LENGTH 500
+#define PGMAP_PRESENT (1UL << 63) +#define KPF_COMPOUND_HEAD (1UL << 15) +#define KPF_COMPOUND_TAIL (1UL << 16) +#define KPF_THP (1UL << 22) +#define PFN_MASK ((1UL<<55)-1) + unsigned int __page_size; unsigned int __page_shift;
@@ -338,6 +344,139 @@ int detect_hugetlb_page_sizes(size_t sizes[], int max) return count; }
+static int get_page_flags(uint64_t vpn, int pagemap_file, int kpageflags_file, + uint64_t *flags) +{ + uint64_t pfn; + size_t count; + + count = pread(pagemap_file, &pfn, sizeof(pfn), + vpn * sizeof(pfn)); + + if (count != sizeof(pfn)) + return -1; + + /* + * Treat non-present page as a page without any flag, so that + * gather_folio_orders() just record the current folio order. + */ + if (!(pfn & PGMAP_PRESENT)) { + *flags = 0; + return 0; + } + + count = pread(kpageflags_file, flags, sizeof(*flags), + (pfn & PFN_MASK) * sizeof(*flags)); + + if (count != sizeof(*flags)) + return -1; + + return 0; +} + +static int gather_folio_orders(uint64_t vpn_start, size_t nr_pages, + int pagemap_file, int kpageflags_file, + int orders[], int nr_orders) +{ + uint64_t page_flags = 0; + int cur_order = -1; + uint64_t vpn; + + if (!pagemap_file || !kpageflags_file) + return -1; + if (nr_orders <= 0) + return -1; + + for (vpn = vpn_start; vpn < vpn_start + nr_pages; ) { + uint64_t next_folio_vpn; + int status; + + if (get_page_flags(vpn, pagemap_file, kpageflags_file, &page_flags)) + return -1; + + /* all order-0 pages with possible false postive (non folio) */ + if (!(page_flags & (KPF_COMPOUND_HEAD | KPF_COMPOUND_TAIL))) { + orders[0]++; + vpn++; + continue; + } + + /* skip non thp compound pages */ + if (!(page_flags & KPF_THP)) { + vpn++; + continue; + } + + /* vpn points to part of a THP at this point */ + if (page_flags & KPF_COMPOUND_HEAD) + cur_order = 1; + else { + /* not a head nor a tail in a THP? */ + if (!(page_flags & KPF_COMPOUND_TAIL)) + return -1; + continue; + } + + next_folio_vpn = vpn + (1 << cur_order); + + if (next_folio_vpn >= vpn_start + nr_pages) + break; + + while (!(status = get_page_flags(next_folio_vpn, pagemap_file, + kpageflags_file, + &page_flags))) { + /* next compound head page or order-0 page */ + if ((page_flags & KPF_COMPOUND_HEAD) || + !(page_flags & (KPF_COMPOUND_HEAD | + KPF_COMPOUND_TAIL))) { + if (cur_order < nr_orders) { + orders[cur_order]++; + cur_order = -1; + vpn = next_folio_vpn; + } + break; + } + + /* not a head nor a tail in a THP? */ + if (!(page_flags & KPF_COMPOUND_TAIL)) + return -1; + + cur_order++; + next_folio_vpn = vpn + (1 << cur_order); + } + + if (status) + return status; + } + if (cur_order > 0 && cur_order < nr_orders) + orders[cur_order]++; + return 0; +} + +int check_folio_orders(uint64_t vpn_start, size_t nr_pages, int pagemap_file, + int kpageflags_file, int orders[], int nr_orders) +{ + int vpn_orders[nr_orders]; + int status; + int i; + + memset(vpn_orders, 0, sizeof(int) * nr_orders); + status = gather_folio_orders(vpn_start, nr_pages, pagemap_file, + kpageflags_file, vpn_orders, nr_orders); + if (status) + return status; + + status = 0; + for (i = 0; i < nr_orders; i++) + if (vpn_orders[i] != orders[i]) { + ksft_print_msg("order %d: expected: %d got %d\n", i, + orders[i], vpn_orders[i]); + status = -1; + } + + return status; +} + /* If `ioctls' non-NULL, the allowed ioctls will be returned into the var */ int uffd_register_with_ioctls(int uffd, void *addr, uint64_t len, bool miss, bool wp, bool minor, uint64_t *ioctls) diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index b55d1809debc..dee9504a6129 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -85,6 +85,8 @@ bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size); int64_t allocate_transhuge(void *ptr, int pagemap_fd); unsigned long default_huge_page_size(void); int detect_hugetlb_page_sizes(size_t sizes[], int max); +int check_folio_orders(uint64_t vpn_start, size_t nr_pages, int pagemap_file, + int kpageflags_file, int orders[], int nr_orders);
int uffd_register(int uffd, void *addr, uint64_t len, bool miss, bool wp, bool minor);