On 10/15/2019 05:16 PM, Michal Hocko wrote: > On Tue 15-10-19 14:51:42, Anshuman Khandual wrote: >> This adds tests which will validate architecture page table helpers and >> other accessors in their compliance with expected generic MM semantics. >> This will help various architectures in validating changes to existing >> page table helpers or addition of new ones. >> >> Test page table and memory pages creating it's entries at various level are >> all allocated from system memory with required size and alignments. But if >> memory pages with required size and alignment could not be allocated, then >> all depending individual tests are just skipped afterwards. This test gets >> called right after init_mm_internals() required for alloc_contig_range() to >> work correctly. >> >> This gets build and run when CONFIG_DEBUG_VM_PGTABLE is selected along with >> CONFIG_VM_DEBUG. Architectures willing to subscribe this test also need to >> select CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE which for now is limited to x86 and >> arm64. Going forward, other architectures too can enable this after fixing >> build or runtime problems (if any) with their page table helpers. > > A highlevel description of tests and what they are testing for would be > really appreciated. Who wants to run these tests and why/when? What kind > of bugs would get detected? In short why do we really need/want this > code in the tree? Sure, will do.