On 6/10/26 4:29 AM, Baolin Wang wrote: > Added a new command 'mthp_khugepaged' for mTHP collapse, along with the '-c' > parameter to specify the collapse order. Additionally, added mTHP collapse > test cases for 'collapse_full', 'collapse_empty', and 'collapse_single_mthp' > for both anonymous pages and shmem. All khugepaged test cases passed. > > Signed-off-by: Baolin Wang <[email protected]> Will rip out the Shmem stuff and test these selftests on top of my mTHP stuff soon :) Ill provide the diff so its easier for you and if I come up with more cases ill add those too. Thanks for doing this!!! -- Nico > --- > tools/testing/selftests/mm/khugepaged.c | 135 +++++++++++++++++++--- > tools/testing/selftests/mm/run_vmtests.sh | 4 + > 2 files changed, 120 insertions(+), 19 deletions(-) > > diff --git a/tools/testing/selftests/mm/khugepaged.c > b/tools/testing/selftests/mm/khugepaged.c > index f69be6be0ecd..8975be5b7b2f 100644 > --- a/tools/testing/selftests/mm/khugepaged.c > +++ b/tools/testing/selftests/mm/khugepaged.c > @@ -26,9 +26,11 @@ > > #define BASE_ADDR ((void *)(1UL << 30)) > static unsigned long hpage_pmd_size; > +static int hpage_pmd_order; > static unsigned long page_size; > static int hpage_pmd_nr; > static int anon_order; > +static int collapse_order; > > #define PID_SMAPS "/proc/self/smaps" > #define TEST_FILE "collapse_test_file" > @@ -69,6 +71,7 @@ struct collapse_context { > }; > > static struct collapse_context *khugepaged_context; > +static struct collapse_context *mthp_khugepaged_context; > static struct collapse_context *madvise_context; > > struct file_info { > @@ -554,25 +557,25 @@ static void madvise_collapse(const char *msg, char *p, > int nr_hpages, > } > > #define TICK 500000 > -static bool wait_for_scan(const char *msg, char *p, int nr_hpages, > - struct mem_ops *ops) > +static bool wait_for_scan(const char *msg, char *p, unsigned long size, > + int nr_hpages, int collap_order, struct mem_ops *ops) > { > - unsigned long size = nr_hpages * hpage_pmd_size; > + unsigned long hpage_size = page_size << collap_order; > int full_scans; > int timeout = 6; /* 3 seconds */ > > /* Sanity check */ > - if (!ops->check_huge(p, size, 0, hpage_pmd_size)) > + if (!ops->check_huge(p, size, 0, hpage_size)) > ksft_exit_fail_msg("Unexpected huge page\n"); > > - madvise(p, nr_hpages * hpage_pmd_size, MADV_HUGEPAGE); > + madvise(p, size, MADV_HUGEPAGE); > > /* Wait until the second full_scan completed */ > full_scans = thp_read_num("khugepaged/full_scans") + 2; > > ksft_print_msg("%s...", msg); > while (timeout--) { > - if (ops->check_huge(p, size, nr_hpages, hpage_pmd_size)) > + if (ops->check_huge(p, size, nr_hpages, hpage_size)) > break; > if (thp_read_num("khugepaged/full_scans") >= full_scans) > break; > @@ -595,7 +598,7 @@ static void khugepaged_collapse(const char *msg, char *p, > int nr_hpages, > if (!is_tmpfs(ops) && ops == &__read_write_file_write_ops) > expect = false; > > - if (wait_for_scan(msg, p, nr_hpages, ops)) { > + if (wait_for_scan(msg, p, size, nr_hpages, hpage_pmd_order, ops)) { > if (expect) > fail("Timeout"); > else > @@ -617,12 +620,65 @@ static void khugepaged_collapse(const char *msg, char > *p, int nr_hpages, > fail("Fail"); > } > > +static void mthp_khugepaged_collapse(const char *msg, char *p, int nr_hpages, > + struct mem_ops *ops, bool expect) > +{ > + unsigned long hpage_size = page_size << collapse_order; > + struct thp_settings settings = *thp_current_settings(); > + /* mTHP collpase only allocates PMD sized memory */ > + unsigned long size = hpage_pmd_size; > + > + /* Set mTHP setting for mTHP collapse */ > + if (ops == &__anon_ops) { > + settings.thp_enabled = THP_NEVER; > + settings.hugepages[collapse_order].enabled = THP_ALWAYS; > + } else if (ops == &__shmem_ops) { > + settings.shmem_enabled = SHMEM_NEVER; > + settings.shmem_hugepages[collapse_order].enabled = SHMEM_ALWAYS; > + } > + > + thp_push_settings(&settings); > + > + if (wait_for_scan(msg, p, size, nr_hpages, collapse_order, ops)) { > + if (expect) > + fail("Timeout"); > + else > + success("OK"); > + > + /* Restore THP settings for mTHP collapse. */ > + thp_pop_settings(); > + return; > + } > + > + /* > + * For file and shmem memory, khugepaged only retracts pte entries after > + * putting the new hugepage in the page cache. The hugepage must be > + * subsequently refaulted to install the pmd mapping for the mm. > + */ > + if (ops != &__anon_ops) > + ops->fault(p, 0, nr_hpages * hpage_size); > + > + if (ops->check_huge(p, size, expect ? nr_hpages : 0, hpage_size)) > + success("OK"); > + else > + fail("Fail"); > + > + /* Restore THP settings for mTHP collapse. */ > + thp_pop_settings(); > +} > + > static struct collapse_context __khugepaged_context = { > .collapse = &khugepaged_collapse, > .enforce_pte_scan_limits = true, > .name = "khugepaged", > }; > > +static struct collapse_context __mthp_khugepaged_context = { > + .collapse = &mthp_khugepaged_collapse, > + .enforce_pte_scan_limits = true, > + .name = "mthp_khugepaged", > +}; > + > static struct collapse_context __madvise_context = { > .collapse = &madvise_collapse, > .enforce_pte_scan_limits = false, > @@ -661,10 +717,17 @@ static void alloc_at_fault(void) > static void collapse_full(struct collapse_context *c, struct mem_ops *ops) > { > void *p; > - int nr_hpages = 4; > + int nr_pmds = 4, nr_hpages = 4; > unsigned long size = nr_hpages * hpage_pmd_size; > > - p = ops->setup_area(nr_hpages); > + /* Only try 1 PMD sized range for mTHP collapse. */ > + if (c == &__mthp_khugepaged_context) { > + nr_pmds = 1; > + nr_hpages = 1 << (hpage_pmd_order - collapse_order); > + size = hpage_pmd_size; > + } > + > + p = ops->setup_area(nr_pmds); > ops->fault(p, 0, size); > c->collapse("Collapse multiple fully populated PTE table", p, nr_hpages, > ops, true); > @@ -676,10 +739,31 @@ static void collapse_full(struct collapse_context *c, > struct mem_ops *ops) > > static void collapse_empty(struct collapse_context *c, struct mem_ops *ops) > { > + int nr_hpages = 1; > + void *p; > + > + if (c == &__mthp_khugepaged_context) > + nr_hpages = 1 << (hpage_pmd_order - collapse_order); > + > + p = ops->setup_area(1); > + c->collapse("Do not collapse empty PTE table", p, nr_hpages, ops, > false); > + ops->cleanup_area(p, hpage_pmd_size); > + ksft_test_result_report(exit_status, "%s\n", __func__); > +} > + > +static void collapse_single_mthp(struct collapse_context *c, struct mem_ops > *ops) > +{ > + unsigned long hpage_size = page_size << collapse_order; > void *p; > > p = ops->setup_area(1); > - c->collapse("Do not collapse empty PTE table", p, 1, ops, false); > + /* > + * Only fault collapse_order sized ranges, and only check 1 > + * collapse_order sized huge page. > + */ > + ops->fault(p, 0, hpage_size); > + c->collapse("Collapse PTE table with half PTE entries present", > + p, 1, ops, true); > ops->cleanup_area(p, hpage_pmd_size); > ksft_test_result_report(exit_status, "%s\n", __func__); > } > @@ -1081,8 +1165,8 @@ static void madvise_retracted_page_tables(struct > collapse_context *c, > ops->fault(p, 0, size); > > /* Let khugepaged collapse and leave pmd cleared */ > - if (wait_for_scan("Collapse and leave PMD cleared", p, nr_hpages, > - ops)) { > + if (wait_for_scan("Collapse and leave PMD cleared", p, size, nr_hpages, > + hpage_pmd_order, ops)) { > fail("Timeout"); > return; > } > @@ -1098,7 +1182,7 @@ static void usage(void) > { > fprintf(stderr, "\nUsage: ./khugepaged [OPTIONS] <test type> > [dir]\n\n"); > fprintf(stderr, "\t<test type>\t: <context>:<mem_type>\n"); > - fprintf(stderr, "\t<context>\t: [all|khugepaged|madvise]\n"); > + fprintf(stderr, "\t<context>\t: > [all|khugepaged|mthp_khugepaged|madvise]\n"); > fprintf(stderr, "\t<mem_type>\t: [all|anon|file|shmem]\n"); > fprintf(stderr, "\n\t\"file,all\" mem_type requires [dir] argument\n"); > fprintf(stderr, "\n\t\"file,all\" mem_type requires a file system\n"); > @@ -1109,6 +1193,7 @@ static void usage(void) > fprintf(stderr, "\t\t-h: This help message.\n"); > fprintf(stderr, "\t\t-s: mTHP size, expressed as page order.\n"); > fprintf(stderr, "\t\t Defaults to 0. Use this size for anon or shmem > allocations.\n"); > + fprintf(stderr, "\t\t-c: collapse order for mTHP collapse, expressed as > page order.\n"); > exit(1); > } > > @@ -1118,11 +1203,14 @@ static void parse_test_type(int argc, char **argv) > char *buf; > const char *token; > > - while ((opt = getopt(argc, argv, "s:h")) != -1) { > + while ((opt = getopt(argc, argv, "s:c:h")) != -1) { > switch (opt) { > case 's': > anon_order = atoi(optarg); > break; > + case 'c': > + collapse_order = atoi(optarg); > + break; > case 'h': > default: > usage(); > @@ -1148,6 +1236,10 @@ static void parse_test_type(int argc, char **argv) > madvise_context = &__madvise_context; > } else if (!strcmp(token, "khugepaged")) { > khugepaged_context = &__khugepaged_context; > + } else if (!strcmp(token, "mthp_khugepaged")) { > + mthp_khugepaged_context = &__mthp_khugepaged_context; > + if (collapse_order == 0 || collapse_order >= hpage_pmd_order) > + usage(); > } else if (!strcmp(token, "madvise")) { > madvise_context = &__madvise_context; > } else { > @@ -1213,7 +1305,6 @@ static int nr_test_cases; > > int main(int argc, char **argv) > { > - int hpage_pmd_order; > struct thp_settings default_settings = { > .thp_enabled = THP_MADVISE, > .thp_defrag = THP_DEFRAG_ALWAYS, > @@ -1239,10 +1330,6 @@ int main(int argc, char **argv) > if (!thp_is_enabled()) > ksft_exit_skip("Transparent Hugepages not available\n"); > > - parse_test_type(argc, argv); > - > - setbuf(stdout, NULL); > - > page_size = getpagesize(); > hpage_pmd_size = read_pmd_pagesize(); > if (!hpage_pmd_size) > @@ -1250,6 +1337,10 @@ int main(int argc, char **argv) > hpage_pmd_nr = hpage_pmd_size / page_size; > hpage_pmd_order = __builtin_ctz(hpage_pmd_nr); > > + parse_test_type(argc, argv); > + > + setbuf(stdout, NULL); > + > default_settings.khugepaged.max_ptes_none = hpage_pmd_nr - 1; > default_settings.khugepaged.max_ptes_swap = hpage_pmd_nr / 8; > default_settings.khugepaged.max_ptes_shared = hpage_pmd_nr / 2; > @@ -1267,6 +1358,8 @@ int main(int argc, char **argv) > TEST(collapse_full, khugepaged_context, read_write_file_read_ops); > TEST(collapse_full, khugepaged_context, read_write_file_write_ops); > TEST(collapse_full, khugepaged_context, shmem_ops); > + TEST(collapse_full, mthp_khugepaged_context, anon_ops); > + TEST(collapse_full, mthp_khugepaged_context, shmem_ops); > TEST(collapse_full, madvise_context, anon_ops); > TEST(collapse_full, madvise_context, read_only_file_ops); > TEST(collapse_full, madvise_context, read_write_file_read_ops); > @@ -1274,8 +1367,12 @@ int main(int argc, char **argv) > TEST(collapse_full, madvise_context, shmem_ops); > > TEST(collapse_empty, khugepaged_context, anon_ops); > + TEST(collapse_empty, mthp_khugepaged_context, anon_ops); > TEST(collapse_empty, madvise_context, anon_ops); > > + TEST(collapse_single_mthp, mthp_khugepaged_context, anon_ops); > + TEST(collapse_single_mthp, mthp_khugepaged_context, shmem_ops); > + > TEST(collapse_single_pte_entry, khugepaged_context, anon_ops); > TEST(collapse_single_pte_entry, khugepaged_context, read_only_file_ops); > TEST(collapse_single_pte_entry, khugepaged_context, > read_write_file_read_ops); > diff --git a/tools/testing/selftests/mm/run_vmtests.sh > b/tools/testing/selftests/mm/run_vmtests.sh > index 8c296dedf047..c0f4f3e5f1f1 100755 > --- a/tools/testing/selftests/mm/run_vmtests.sh > +++ b/tools/testing/selftests/mm/run_vmtests.sh > @@ -411,6 +411,10 @@ CATEGORY="thp" run_test ./khugepaged all:shmem > > CATEGORY="thp" run_test ./khugepaged -s 4 all:shmem > > +CATEGORY="thp" run_test ./khugepaged -c 4 mthp_khugepaged:anon > + > +CATEGORY="thp" run_test ./khugepaged -c 4 mthp_khugepaged:shmem > + > # Try to create XFS if not provided > if [ -z "${SPLIT_HUGE_PAGE_TEST_XFS_PATH}" ]; then > if test_selected "thp"; then
