On 02/05/2024 03:43, Anshuman Khandual wrote: > Hello Ryan, > > On 5/1/24 20:14, Ryan Roberts wrote: >> An invalidated pmd should still cause pmd_leaf() to return true. Let's >> test for that to ensure all arches remain consistent. > > This test definitely makes sense. > >> >> Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx> >> --- >> >> Hi Andrew, >> >> This applies on top of v6.9-rc5. It came out of a discussion with Catalin around >> the pmd_mkinvalid() bug (the fix for which I just posted). I've run the new test >> on both arm64 and x86_64. > > Right, works on arm64. > >> >> Thanks, >> Ryan >> >> mm/debug_vm_pgtable.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c >> index 65c19025da3d..57e9cb0820ab 100644 >> --- a/mm/debug_vm_pgtable.c >> +++ b/mm/debug_vm_pgtable.c >> @@ -981,6 +981,7 @@ static void __init pmd_thp_tests(struct pgtable_debug_args *args) >> #ifndef __HAVE_ARCH_PMDP_INVALIDATE >> WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd)))); >> WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd)))); >> + WARN_ON(!pmd_leaf(pmd_mkinvalid(pmd_mkhuge(pmd)))); >> #endif /* __HAVE_ARCH_PMDP_INVALIDATE */ >> } > > Should not we update descriptions in Documentation/mm/arch_pgtable_helpers.rst > asserting that pmd_mkinvalid() also preserves pmd_leaf() ? Thanks for the review! We don't document that pmd_mkinvalid() preserves pmd_present() and pmd_trans_huge() so I wasn't sure how much detail was appropriate in that document - its pretty light at the moment. If you think this is valuable (and isn't clear enough from the test) then I can add something. But as you say in the other patch, it would then start conflicting with that. I'd prefer to just put this in as-is to avoid the mess.
