This series adds a test validation for architecture exported page table helpers. Patch in the series adds basic transformation tests at various levels of the page table.
This test was originally suggested by Catalin during arm64 THP migration RFC discussion earlier. Going forward it can include more specific tests with respect to various generic MM functions like THP, HugeTLB etc and platform specific tests. https://lore.kernel.org/linux-mm/[email protected]/ Questions: Should alloc_gigantic_page() be made available as an interface for general use in the kernel. The test module here uses very similar implementation from HugeTLB to allocate a PUD aligned memory block. Similar for mm_alloc() which needs to be exported through a header. Testing: Build and boot tested on arm64 and x86 platforms. While arm64 clears all these tests, following errors were reported on x86. 1. WARN_ON(pud_bad(pud)) in pud_populate_tests() 2. WARN_ON(p4d_bad(p4d)) in p4d_populate_tests() I would really appreciate if folks can help validate this test on other platforms and report back problems if any. Suggestions, comments and inputs welcome. Thank you. Changes in V2: - Moved test module and it's config from lib/ to mm/ - Renamed config TEST_ARCH_PGTABLE as DEBUG_ARCH_PGTABLE_TEST - Renamed file from test_arch_pgtable.c to arch_pgtable_test.c - Added relevant MODULE_DESCRIPTION() and MODULE_AUTHOR() details - Dropped loadable module config option - Basic tests now use memory blocks with required size and alignment - PUD aligned memory block gets allocated with alloc_contig_range() - If PUD aligned memory could not be allocated it falls back on PMD aligned memory block from page allocator and pud_* tests are skipped - Clear and populate tests now operate on real in memory page table entries - Dummy mm_struct gets allocated with mm_alloc() - Dummy page table entries get allocated with [pud|pmd|pte]_alloc_[map]() - Simplified [p4d|pgd]_basic_tests(), now has random values in the entries RFC V1: https://lore.kernel.org/linux-mm/[email protected]/ Cc: Andrew Morton <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Dan Williams <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Mark Brown <[email protected]> Cc: Steven Price <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Kees Cook <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Sri Krishna chowdary <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Russell King - ARM Linux <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: James Hogan <[email protected]> Cc: Paul Burton <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Anshuman Khandual (1): mm/pgtable/debug: Add test validating architecture page table helpers mm/Kconfig.debug | 14 ++ mm/Makefile | 1 + mm/arch_pgtable_test.c | 400 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 415 insertions(+) create mode 100644 mm/arch_pgtable_test.c -- 2.20.1
