gup_test.c currently serves two distinct purposes: microbenchmarking (GUP_FAST_BENCHMARK, PIN_FAST_BENCHMARK, PIN_LONGTERM_BENCHMARK) and functional correctness testing (GUP_BASIC_TEST, PIN_BASIC_TEST, DUMP_USER_PAGES_TEST). Mixing these in a single binary means that functional tests cannot be run or reported individually, and run_vmtests.sh must invoke the binary multiple times with different flag combinations to cover all configurations.
This series separates the two concerns: tools/mm/gup_bench handles benchmarking, while tools/testing/selftests/mm/gup_test handles functional testing. To avoid duplicating the HugeTLB and related file helpers, the series first prepares the existing helpers for sharing, then moves the common code to tools/lib/mm/ for use by both selftests and tools/mm. Patch 1 makes read_file(), write_file(), read_num() and write_num() in vm_util.c return errors to callers rather than exiting. It also makes read_num() reject negative, malformed and out-of-range values. Existing mm selftest callers are updated to report failures through kselftest helpers. This avoids carrying behavior specific to selftests into the shared helper implementation introduced in the next patch. Patch 2 adds tools/lib/mm/file_utils.[ch], moving read_file(), write_file(), read_num() and write_num() out of vm_util.c into a shared helper without a kselftest dependency. It keeps the helpers available to mm selftests through vm_util.h, updates the explicit x86 protection_keys build rules to preserve full prerequisite paths, and adds tools/lib/mm/ to the MEMORY MANAGEMENT - MISC entry in MAINTAINERS. Patch 3 moves hugepage_settings.[ch] from selftests/mm to tools/lib/mm/. It keeps the helpers available to selftests through vm_util.h where possible, uses direct <mm/hugepage_settings.h> includes for users that do not include vm_util.h, and removes the remaining kselftest dependency from the implementation. The existing HugeTLB diagnostic messages are preserved as TAP-compatible printf() diagnostics. Patch 4 adds tools/mm/gup_bench.c, a standalone microbenchmark for GUP_FAST, PIN_FAST and PIN_LONGTERM through the CONFIG_GUP_TEST debugfs interface. It runs the benchmark subset of the configuration matrix previously covered by run_gup_matrix(), covering all three benchmark commands, read and write GUP access, private and shared mappings, four page counts, and THP, non-THP and hugetlb mappings. It also restores HugeTLB settings after each hugetlb benchmark run and validates command-line arguments, including their numeric ranges. Patch 5 rewrites gup_test.c to use the kselftest harness. It covers all five GUP/PUP kernel functions (get_user_pages, get_user_pages_fast, pin_user_pages, pin_user_pages_fast, and pin_user_pages with FOLL_LONGTERM), plus DUMP_USER_PAGES_TEST, across 12 mapping configurations. These configurations cover THP, non-THP and hugetlb mappings, each with private and shared mappings and read and write access. Each configuration is tested with four batch sizes (1, 512, 123, and all pages). The patch also preserves the old sparse dump coverage for pages 0, 19 and 0x1000. Results are reported in standard TAP format, with no command-line arguments required. --- Changes in v5: - Rebase onto v7.2-rc3 - Address feedback from Mike, John, Dev and Sashiko - Make file helper diagnostics TAP-compatible - Validate read_num() input and propagate errors while restoring shared memory limits - Preserve build bisectability for the x86 protection_keys test - Preserve HugeTLB diagnostics using TAP-compatible printf() output - Validate the remaining numeric arguments accepted by gup_bench Changes in v4: - Address review feedback from Mike and Sashiko - Add a preparatory patch so shared file helpers return errors instead of exiting - Reduce include churn by keeping shared helpers exposed through vm_util.h - Preserve HugeTLB diagnostics and restore HugeTLB state more carefully - Fix selftests/mm build details after moving helpers to tools/lib/mm - Tighten gup_bench argument handling and gup_test setup/sparse-dump coverage Changes in v3: - Address v2 feedback from Sashiko - Add shared file_utils helpers under tools/lib/mm - Move hugepage_settings out of selftests and into tools/lib/mm - Convert gup_bench to use the shared tools/lib/mm helpers - Guard against invalid thread counts in gup_bench - Handle thread-array allocation failure cleanly in gup_bench - Restore hugetlb settings on setup failure in gup_test - Add sparse DUMP_USER_PAGES_TEST coverage for pages 0, 19 and 0x1000 in gup_test Changes in v2: - Address v1 feedback from Sashiko - Add fast and longterm GUP/PUP coverage - Sweep nr_pages_per_call over 1, 512, 123 and all pages - Call madvise(MADV_NOHUGEPAGE) in non-THP variants - Use 256 MB for hugetlb fixtures - Use hugetlb_restore_settings() in FIXTURE_TEARDOWN instead of atexit() - Add TH_LOG to report nr_pages_per_call for each iteration - Update Documentation/core-api/pin_user_pages.rst unit testing section Previous versions: v4: lore.kernel.org/all/[email protected]/ v3: lore.kernel.org/all/[email protected]/ v2: lore.kernel.org/all/[email protected]/ v1: lore.kernel.org/all/[email protected]/ --- Sarthak Sharma (5): selftests/mm: make file helpers return errors tools/lib/mm: add shared file helpers tools/lib/mm: move hugepage_settings out of selftests tools/mm: add a standalone GUP microbenchmark selftests/mm: rewrite gup_test as a standalone harness-based selftest Documentation/core-api/pin_user_pages.rst | 12 +- MAINTAINERS | 2 + tools/lib/mm/file_utils.c | 119 ++++ tools/lib/mm/file_utils.h | 12 + .../selftests => lib}/mm/hugepage_settings.c | 81 ++- .../selftests => lib}/mm/hugepage_settings.h | 0 tools/mm/.gitignore | 2 + tools/mm/Makefile | 10 +- tools/mm/gup_bench.c | 482 ++++++++++++++ tools/testing/selftests/mm/Makefile | 13 +- tools/testing/selftests/mm/compaction_test.c | 2 +- tools/testing/selftests/mm/cow.c | 1 - .../selftests/mm/folio_split_race_test.c | 1 - tools/testing/selftests/mm/guard-regions.c | 1 - tools/testing/selftests/mm/gup_longterm.c | 1 - tools/testing/selftests/mm/gup_test.c | 606 +++++++++++------- tools/testing/selftests/mm/hmm-tests.c | 6 +- tools/testing/selftests/mm/hugetlb-madvise.c | 1 - tools/testing/selftests/mm/hugetlb-mmap.c | 1 - tools/testing/selftests/mm/hugetlb-mremap.c | 1 - tools/testing/selftests/mm/hugetlb-shm.c | 1 - .../selftests/mm/hugetlb-soft-offline.c | 2 +- tools/testing/selftests/mm/hugetlb-vmemmap.c | 1 - tools/testing/selftests/mm/hugetlb_dio.c | 1 - .../selftests/mm/hugetlb_fault_after_madv.c | 1 - .../selftests/mm/hugetlb_madv_vs_map.c | 1 - tools/testing/selftests/mm/khugepaged.c | 14 +- tools/testing/selftests/mm/ksm_tests.c | 1 - tools/testing/selftests/mm/migration.c | 5 +- tools/testing/selftests/mm/pagemap_ioctl.c | 1 - .../testing/selftests/mm/prctl_thp_disable.c | 1 - tools/testing/selftests/mm/protection_keys.c | 2 +- tools/testing/selftests/mm/run_vmtests.sh | 37 +- tools/testing/selftests/mm/soft-dirty.c | 1 - .../selftests/mm/split_huge_page_test.c | 5 +- tools/testing/selftests/mm/thuge-gen.c | 1 - tools/testing/selftests/mm/transhuge-stress.c | 1 - tools/testing/selftests/mm/uffd-common.h | 1 - tools/testing/selftests/mm/uffd-wp-mremap.c | 2 +- .../selftests/mm/va_high_addr_switch.c | 1 - tools/testing/selftests/mm/vm_util.c | 88 +-- tools/testing/selftests/mm/vm_util.h | 7 +- 42 files changed, 1131 insertions(+), 398 deletions(-) create mode 100644 tools/lib/mm/file_utils.c create mode 100644 tools/lib/mm/file_utils.h rename tools/{testing/selftests => lib}/mm/hugepage_settings.c (91%) rename tools/{testing/selftests => lib}/mm/hugepage_settings.h (100%) create mode 100644 tools/mm/gup_bench.c base-commit: a13c140cc289c0b7b3770bce5b3ad42ab35074aa -- 2.39.5
