On 6/10/26 4:29 AM, Baolin Wang wrote:
> To support checking for various sized mTHPs during mTHP collapse, extend the
> check_huge() function prototype to accept two new parameters specifying the
> address range and mTHP size, in preparation for the following patches.
>
> No functional changes.
>
> Signed-off-by: Baolin Wang <[email protected]>
> ---
> .../selftests/mm/folio_split_race_test.c | 2 +-
> tools/testing/selftests/mm/khugepaged.c | 66 ++++++++++---------
> .../testing/selftests/mm/prctl_thp_disable.c | 2 +-
> tools/testing/selftests/mm/soft-dirty.c | 2 +-
> .../selftests/mm/split_huge_page_test.c | 14 ++--
> tools/testing/selftests/mm/uffd-common.c | 4 +-
> tools/testing/selftests/mm/vm_util.c | 6 +-
> tools/testing/selftests/mm/vm_util.h | 6 +-
> 8 files changed, 55 insertions(+), 47 deletions(-)
>
> diff --git a/tools/testing/selftests/mm/folio_split_race_test.c
> b/tools/testing/selftests/mm/folio_split_race_test.c
> index 6329e37fff4c..45b84f7b364e 100644
> --- a/tools/testing/selftests/mm/folio_split_race_test.c
> +++ b/tools/testing/selftests/mm/folio_split_race_test.c
> @@ -182,7 +182,7 @@ static uint64_t run_iteration(void)
> for (i = 0; i < TOTAL_PAGES; i++)
> fill_page(mmap_base, i);
>
> - if (!check_huge_shmem(mmap_base, NR_PMD_PAGE, pmd_pagesize))
> + if (!check_huge_shmem(mmap_base, FILE_SIZE, NR_PMD_PAGE, pmd_pagesize))
> ksft_exit_fail_msg("No shmem THP is allocated\n");
>
> if (pthread_barrier_init(&ctl.barrier, NULL, NUM_READER_THREADS + 1) !=
> 0)
> diff --git a/tools/testing/selftests/mm/khugepaged.c
> b/tools/testing/selftests/mm/khugepaged.c
> index 10e8dedcb087..f69be6be0ecd 100644
> --- a/tools/testing/selftests/mm/khugepaged.c
> +++ b/tools/testing/selftests/mm/khugepaged.c
> @@ -51,7 +51,7 @@ struct mem_ops {
> void *(*setup_area)(int nr_hpages);
> void (*cleanup_area)(void *p, unsigned long size);
> void (*fault)(void *p, unsigned long start, unsigned long end);
> - bool (*check_huge)(void *addr, int nr_hpages);
> + bool (*check_huge)(void *addr, unsigned long size, int nr_hpages,
> unsigned long hpage_size);
> const char *name;
> };
>
> @@ -276,7 +276,7 @@ static void *alloc_hpage(struct mem_ops *ops)
> ksft_print_msg("Allocate huge page...");
> if (madvise_collapse_retry(p, hpage_pmd_size))
> ksft_exit_fail_perror("madvise(MADV_COLLAPSE)");
> - if (!ops->check_huge(p, 1))
> + if (!ops->check_huge(p, hpage_pmd_size, 1, hpage_pmd_size))
> ksft_exit_fail_perror("madvise(MADV_COLLAPSE)");
> if (madvise(p, hpage_pmd_size, MADV_HUGEPAGE))
> ksft_exit_fail_perror("madvise(MADV_HUGEPAGE)");
> @@ -310,9 +310,10 @@ static void anon_fault(void *p, unsigned long start,
> unsigned long end)
> fill_memory(p, start, end);
> }
>
> -static bool anon_check_huge(void *addr, int nr_hpages)
> +static bool anon_check_huge(void *addr, unsigned long size,
> + int nr_hpages, unsigned long hpage_size)
> {
> - return check_huge_anon(addr, nr_hpages, hpage_pmd_size);
> + return check_huge_anon(addr, size, nr_hpages, hpage_size);
> }
>
> static void *file_setup_area_common(int nr_hpages, enum file_setup_ops setup)
> @@ -412,13 +413,14 @@ static void file_fault_write(void *p, unsigned long
> start, unsigned long end)
> ksft_exit_fail_perror("madvise(MADV_POPULATE_WRITE)");
> }
>
> -static bool file_check_huge(void *addr, int nr_hpages)
> +static bool file_check_huge(void *addr, unsigned long size,
> + int nr_hpages, unsigned long hpage_size)
> {
> switch (finfo.type) {
> case VMA_FILE:
> - return check_huge_file(addr, nr_hpages, hpage_pmd_size);
> + return check_huge_file(addr, size, nr_hpages, hpage_size);
> case VMA_SHMEM:
> - return check_huge_shmem(addr, nr_hpages, hpage_pmd_size);
> + return check_huge_shmem(addr, size, nr_hpages, hpage_size);
> default:
> exit(EXIT_FAILURE);
> return false;
> @@ -448,9 +450,10 @@ static void shmem_cleanup_area(void *p, unsigned long
> size)
> close(finfo.fd);
> }
>
> -static bool shmem_check_huge(void *addr, int nr_hpages)
> +static bool shmem_check_huge(void *addr, unsigned long size,
> + int nr_hpages, unsigned long hpage_size)
> {
> - return check_huge_shmem(addr, nr_hpages, hpage_pmd_size);
> + return check_huge_shmem(addr, size, nr_hpages, hpage_size);
> }
>
> static struct mem_ops __anon_ops = {
> @@ -533,7 +536,7 @@ static void __madvise_collapse(const char *msg, char *p,
> int nr_hpages,
> ret = madvise_collapse_retry(p, nr_hpages * hpage_pmd_size);
> if (((bool)ret) == expect)
> fail("Fail: Bad return value");
> - else if (!ops->check_huge(p, expect ? nr_hpages : 0))
> + else if (!ops->check_huge(p, nr_hpages * hpage_pmd_size, expect ?
> nr_hpages : 0, hpage_pmd_size))
> fail("Fail: check_huge()");
> else
> success("OK");
> @@ -545,7 +548,7 @@ static void madvise_collapse(const char *msg, char *p,
> int nr_hpages,
> struct mem_ops *ops, bool expect)
> {
> /* Sanity check */
> - if (!ops->check_huge(p, 0))
> + if (!ops->check_huge(p, nr_hpages * hpage_pmd_size, 0, hpage_pmd_size))
> ksft_exit_fail_msg("Unexpected huge page\n");
> __madvise_collapse(msg, p, nr_hpages, ops, expect);
> }
> @@ -554,11 +557,12 @@ static void madvise_collapse(const char *msg, char *p,
> int nr_hpages,
> static bool wait_for_scan(const char *msg, char *p, int nr_hpages,
> struct mem_ops *ops)
> {
> + unsigned long size = nr_hpages * hpage_pmd_size;
> int full_scans;
> int timeout = 6; /* 3 seconds */
>
> /* Sanity check */
> - if (!ops->check_huge(p, 0))
> + if (!ops->check_huge(p, size, 0, hpage_pmd_size))
> ksft_exit_fail_msg("Unexpected huge page\n");
>
> madvise(p, nr_hpages * hpage_pmd_size, MADV_HUGEPAGE);
> @@ -568,7 +572,7 @@ static bool wait_for_scan(const char *msg, char *p, int
> nr_hpages,
>
> ksft_print_msg("%s...", msg);
> while (timeout--) {
> - if (ops->check_huge(p, nr_hpages))
> + if (ops->check_huge(p, size, nr_hpages, hpage_pmd_size))
> break;
> if (thp_read_num("khugepaged/full_scans") >= full_scans)
> break;
> @@ -582,6 +586,8 @@ static bool wait_for_scan(const char *msg, char *p, int
> nr_hpages,
> static void khugepaged_collapse(const char *msg, char *p, int nr_hpages,
> struct mem_ops *ops, bool expect)
> {
> + unsigned long size = nr_hpages * hpage_pmd_size;
> +
> /*
> * read&write file collapse fails since khugepaged does not flush
> * the target dirty folios
> @@ -605,7 +611,7 @@ static void khugepaged_collapse(const char *msg, char *p,
> int nr_hpages,
> if (ops != &__anon_ops)
> ops->fault(p, 0, nr_hpages * hpage_pmd_size);
>
> - if (ops->check_huge(p, expect ? nr_hpages : 0))
> + if (ops->check_huge(p, size, expect ? nr_hpages : 0, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -634,7 +640,7 @@ static void alloc_at_fault(void)
> p = alloc_mapping(1);
> *p = 1;
> ksft_print_msg("Allocate huge page on fault...");
> - if (check_huge_anon(p, 1, hpage_pmd_size))
> + if (check_huge_anon(p, hpage_pmd_size, 1, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -643,7 +649,7 @@ static void alloc_at_fault(void)
>
> madvise(p, page_size, MADV_DONTNEED);
> ksft_print_msg("Split huge PMD on MADV_DONTNEED...");
> - if (check_huge_anon(p, 0, hpage_pmd_size))
> + if (check_huge_anon(p, hpage_pmd_size, 0, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -815,7 +821,7 @@ static void collapse_single_pte_entry_compound(struct
> collapse_context *c, struc
> madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE);
> ksft_print_msg("Split huge page leaving single PTE mapping compound
> page...");
> madvise(p + page_size, hpage_pmd_size - page_size, MADV_DONTNEED);
> - if (ops->check_huge(p, 0))
> + if (ops->check_huge(p, hpage_pmd_size, 0, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -836,7 +842,7 @@ static void collapse_full_of_compound(struct
> collapse_context *c, struct mem_ops
> ksft_print_msg("Split huge page leaving single PTE page table full of
> compound pages...");
> madvise(p, page_size, MADV_NOHUGEPAGE);
> madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE);
> - if (ops->check_huge(p, 0))
> + if (ops->check_huge(p, hpage_pmd_size, 0, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -858,7 +864,7 @@ static void collapse_compound_extreme(struct
> collapse_context *c, struct mem_ops
> for (i = 0; i < hpage_pmd_nr; i++) {
> madvise(BASE_ADDR, hpage_pmd_size, MADV_HUGEPAGE);
> ops->fault(BASE_ADDR, 0, hpage_pmd_size);
> - if (!ops->check_huge(BASE_ADDR, 1))
> + if (!ops->check_huge(BASE_ADDR, hpage_pmd_size, 1,
> hpage_pmd_size))
> ksft_exit_fail_msg("Failed to allocate huge page\n");
> madvise(BASE_ADDR, hpage_pmd_size, MADV_NOHUGEPAGE);
>
> @@ -881,7 +887,7 @@ static void collapse_compound_extreme(struct
> collapse_context *c, struct mem_ops
>
> ops->cleanup_area(BASE_ADDR, hpage_pmd_size);
> ops->fault(p, 0, hpage_pmd_size);
> - if (!ops->check_huge(p, 1))
> + if (!ops->check_huge(p, hpage_pmd_size, 1, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -903,7 +909,7 @@ static void collapse_fork(struct collapse_context *c,
> struct mem_ops *ops)
>
> ksft_print_msg("Allocate small page...");
> ops->fault(p, 0, page_size);
> - if (ops->check_huge(p, 0))
> + if (ops->check_huge(p, hpage_pmd_size, 0, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -911,7 +917,7 @@ static void collapse_fork(struct collapse_context *c,
> struct mem_ops *ops)
> ksft_print_msg("Share small page over fork()...");
> if (!fork()) {
> /* Do not touch settings on child exit */
> - if (ops->check_huge(p, 0))
> + if (ops->check_huge(p, hpage_pmd_size, 0, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -929,7 +935,7 @@ static void collapse_fork(struct collapse_context *c,
> struct mem_ops *ops)
> exit_status = WEXITSTATUS(wstatus);
>
> ksft_print_msg("Check if parent still has small page...");
> - if (ops->check_huge(p, 0))
> + if (ops->check_huge(p, hpage_pmd_size, 0, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -947,7 +953,7 @@ static void collapse_fork_compound(struct
> collapse_context *c, struct mem_ops *o
> ksft_print_msg("Share huge page over fork()...");
> if (!fork()) {
> /* Do not touch settings on child exit */
> - if (ops->check_huge(p, 1))
> + if (ops->check_huge(p, hpage_pmd_size, 1, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -955,7 +961,7 @@ static void collapse_fork_compound(struct
> collapse_context *c, struct mem_ops *o
> ksft_print_msg("Split huge page PMD in child process...");
> madvise(p, page_size, MADV_NOHUGEPAGE);
> madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE);
> - if (ops->check_huge(p, 0))
> + if (ops->check_huge(p, hpage_pmd_size, 0, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -976,7 +982,7 @@ static void collapse_fork_compound(struct
> collapse_context *c, struct mem_ops *o
> exit_status = WEXITSTATUS(wstatus);
>
> ksft_print_msg("Check if parent still has huge page...");
> - if (ops->check_huge(p, 1))
> + if (ops->check_huge(p, hpage_pmd_size, 1, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -995,7 +1001,7 @@ static void collapse_max_ptes_shared(struct
> collapse_context *c, struct mem_ops
> ksft_print_msg("Share huge page over fork()...");
> if (!fork()) {
> /* Do not touch settings on child exit */
> - if (ops->check_huge(p, 1))
> + if (ops->check_huge(p, hpage_pmd_size, 1, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -1003,7 +1009,7 @@ static void collapse_max_ptes_shared(struct
> collapse_context *c, struct mem_ops
> ksft_print_msg("Trigger CoW on page %d of %d...",
> hpage_pmd_nr - max_ptes_shared - 1,
> hpage_pmd_nr);
> ops->fault(p, 0, (hpage_pmd_nr - max_ptes_shared - 1) *
> page_size);
> - if (ops->check_huge(p, 0))
> + if (ops->check_huge(p, hpage_pmd_size, 0, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -1016,7 +1022,7 @@ static void collapse_max_ptes_shared(struct
> collapse_context *c, struct mem_ops
> hpage_pmd_nr - max_ptes_shared, hpage_pmd_nr);
> ops->fault(p, 0, (hpage_pmd_nr - max_ptes_shared) *
> page_size);
> - if (ops->check_huge(p, 0))
> + if (ops->check_huge(p, hpage_pmd_size, 0,
> hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> @@ -1034,7 +1040,7 @@ static void collapse_max_ptes_shared(struct
> collapse_context *c, struct mem_ops
> exit_status = WEXITSTATUS(wstatus);
>
> ksft_print_msg("Check if parent still has huge page...");
> - if (ops->check_huge(p, 1))
> + if (ops->check_huge(p, hpage_pmd_size, 1, hpage_pmd_size))
> success("OK");
> else
> fail("Fail");
> diff --git a/tools/testing/selftests/mm/prctl_thp_disable.c
> b/tools/testing/selftests/mm/prctl_thp_disable.c
> index d8d9d1de57b8..82c6e96ea6eb 100644
> --- a/tools/testing/selftests/mm/prctl_thp_disable.c
> +++ b/tools/testing/selftests/mm/prctl_thp_disable.c
> @@ -67,7 +67,7 @@ static int test_mmap_thp(enum thp_collapse_type
> madvise_buf, size_t pmdsize)
> /* HACK: make sure we have a separate VMA that we can check reliably. */
> mprotect(mem, pmdsize, PROT_READ);
>
> - ret = check_huge_anon(mem, 1, pmdsize);
> + ret = check_huge_anon(mem, pmdsize, 1, pmdsize);
> munmap(mmap_mem, mmap_size);
> return ret;
> }
> diff --git a/tools/testing/selftests/mm/soft-dirty.c
> b/tools/testing/selftests/mm/soft-dirty.c
> index fb1864a68e1c..e198facf78bb 100644
> --- a/tools/testing/selftests/mm/soft-dirty.c
> +++ b/tools/testing/selftests/mm/soft-dirty.c
> @@ -103,7 +103,7 @@ static void test_hugepage(int pagemap_fd, int pagesize)
> for (i = 0; i < hpage_len; i++)
> map[i] = (char)i;
>
> - if (check_huge_anon(map, 1, hpage_len)) {
> + if (check_huge_anon(map, hpage_len, 1, hpage_len)) {
> ksft_test_result_pass("Test %s huge page allocation\n",
> __func__);
>
> clear_softdirty();
> diff --git a/tools/testing/selftests/mm/split_huge_page_test.c
> b/tools/testing/selftests/mm/split_huge_page_test.c
> index 32b991472f74..4cc70873a674 100644
> --- a/tools/testing/selftests/mm/split_huge_page_test.c
> +++ b/tools/testing/selftests/mm/split_huge_page_test.c
> @@ -296,7 +296,7 @@ static void
> verify_rss_anon_split_huge_page_all_zeroes(char *one_page, int nr_hp
> unsigned long rss_anon_before, rss_anon_after;
> size_t i;
>
> - if (!check_huge_anon(one_page, nr_hpages, pmd_pagesize))
> + if (!check_huge_anon(one_page, nr_hpages * pmd_pagesize, nr_hpages,
> pmd_pagesize))
> ksft_exit_fail_msg("No THP is allocated\n");
>
> rss_anon_before = rss_anon();
> @@ -311,7 +311,7 @@ static void
> verify_rss_anon_split_huge_page_all_zeroes(char *one_page, int nr_hp
> if (one_page[i] != (char)0)
> ksft_exit_fail_msg("%ld byte corrupted\n", i);
>
> - if (!check_huge_anon(one_page, 0, pmd_pagesize))
> + if (!check_huge_anon(one_page, nr_hpages * pmd_pagesize, 0,
> pmd_pagesize))
> ksft_exit_fail_msg("Still AnonHugePages not split\n");
>
> rss_anon_after = rss_anon();
> @@ -347,7 +347,7 @@ static void split_pmd_thp_to_order(int order)
> for (i = 0; i < len; i++)
> one_page[i] = (char)i;
>
> - if (!check_huge_anon(one_page, 4, pmd_pagesize))
> + if (!check_huge_anon(one_page, 4 * pmd_pagesize, 4, pmd_pagesize))
> ksft_exit_fail_msg("No THP is allocated\n");
>
> /* split all THPs */
> @@ -366,7 +366,7 @@ static void split_pmd_thp_to_order(int order)
> (pmd_order + 1)))
> ksft_exit_fail_msg("Unexpected THP split\n");
>
> - if (!check_huge_anon(one_page, 0, pmd_pagesize))
> + if (!check_huge_anon(one_page, 4 * pmd_pagesize, 0, pmd_pagesize))
> ksft_exit_fail_msg("Still AnonHugePages not split\n");
>
> ksft_test_result_pass("Split huge pages to order %d successful\n",
> order);
> @@ -393,7 +393,7 @@ static void split_pte_mapped_thp(void)
> for (i = 0; i < thp_area_size; i++)
> thp_area[i] = (char)i;
>
> - if (!check_huge_anon(thp_area, nr_thps, pmd_pagesize)) {
> + if (!check_huge_anon(thp_area, nr_thps * pmd_pagesize, nr_thps,
> pmd_pagesize)) {
> ksft_test_result_skip("Not all THPs allocated\n");
> goto out;
> }
> @@ -657,7 +657,7 @@ static int create_pagecache_thp_and_fd(const char
> *testfile, size_t fd_size,
>
> force_read_pages(*addr, fd_size / pmd_pagesize, pmd_pagesize);
>
> - if (!check_huge_file(*addr, fd_size / pmd_pagesize, pmd_pagesize)) {
> + if (!check_huge_file(*addr, fd_size, fd_size / pmd_pagesize,
> pmd_pagesize)) {
> ksft_print_msg("No large pagecache folio generated, please
> provide a filesystem supporting large folio\n");
> munmap(*addr, fd_size);
> close(*fd);
> @@ -735,7 +735,7 @@ static void split_thp_in_pagecache_to_order_at(size_t
> fd_size,
> goto out;
> }
>
> - if (!check_huge_file(addr, 0, pmd_pagesize)) {
> + if (!check_huge_file(addr, fd_size, 0, pmd_pagesize)) {
> ksft_print_msg("Still FilePmdMapped not split\n");
> err = EXIT_FAILURE;
> goto out;
> diff --git a/tools/testing/selftests/mm/uffd-common.c
> b/tools/testing/selftests/mm/uffd-common.c
> index edd02328f77b..777f276044e2 100644
> --- a/tools/testing/selftests/mm/uffd-common.c
> +++ b/tools/testing/selftests/mm/uffd-common.c
> @@ -194,7 +194,9 @@ static void shmem_alias_mapping(uffd_global_test_opts_t
> *gopts, __u64 *start,
>
> static void shmem_check_pmd_mapping(uffd_global_test_opts_t *gopts, void *p,
> int expect_nr_hpages)
> {
> - if (!check_huge_shmem(gopts->area_dst_alias, expect_nr_hpages,
> + unsigned long size = expect_nr_hpages * read_pmd_pagesize();
> +
> + if (!check_huge_shmem(gopts->area_dst_alias, size, expect_nr_hpages,
> read_pmd_pagesize()))
> err("Did not find expected %d number of hugepages",
> expect_nr_hpages);
> diff --git a/tools/testing/selftests/mm/vm_util.c
> b/tools/testing/selftests/mm/vm_util.c
> index 311fc5b4513e..b43adfa92116 100644
> --- a/tools/testing/selftests/mm/vm_util.c
> +++ b/tools/testing/selftests/mm/vm_util.c
> @@ -247,17 +247,17 @@ bool __check_huge(void *addr, char *pattern, int
> nr_hpages,
> return thp == (nr_hpages * (hpage_size >> 10));
> }
>
> -bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size)
> +bool check_huge_anon(void *addr, unsigned long size, int nr_hpages, uint64_t
> hpage_size)
Whats the purpose of adding 'size' here?
> {
> return __check_huge(addr, "AnonHugePages: ", nr_hpages, hpage_size);
> }
>
> -bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size)
> +bool check_huge_file(void *addr, unsigned long size, int nr_hpages, uint64_t
> hpage_size)
> {
> return __check_huge(addr, "FilePmdMapped:", nr_hpages, hpage_size);
Same?
> }
>
> -bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size)
> +bool check_huge_shmem(void *addr, unsigned long size, int nr_hpages,
> uint64_t hpage_size)
> {
> return __check_huge(addr, "ShmemPmdMapped:", nr_hpages, hpage_size);
And here?
Perhaps I find out in the next patch :)
Thanks!
-- Nico
> }
> diff --git a/tools/testing/selftests/mm/vm_util.h
> b/tools/testing/selftests/mm/vm_util.h
> index ea8fc8fdf0eb..40c6d8c4f1b8 100644
> --- a/tools/testing/selftests/mm/vm_util.h
> +++ b/tools/testing/selftests/mm/vm_util.h
> @@ -90,9 +90,9 @@ void clear_softdirty(void);
> bool check_for_pattern(FILE *fp, const char *pattern, char *buf, size_t len);
> uint64_t read_pmd_pagesize(void);
> unsigned long rss_anon(void);
> -bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size);
> -bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size);
> -bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size);
> +bool check_huge_anon(void *addr, unsigned long size, int nr_hpages, uint64_t
> hpage_size);
> +bool check_huge_file(void *addr, unsigned long size, int nr_hpages, uint64_t
> hpage_size);
> +bool check_huge_shmem(void *addr, unsigned long size, int nr_hpages,
> uint64_t hpage_size);
> int64_t allocate_transhuge(void *ptr, int pagemap_fd);
> int pageflags_get(unsigned long pfn, int kpageflags_fd, uint64_t *flags);
>
