On 7/22/21 12:07 PM, Gavin Shan wrote: > >>> pgdp = pgd_offset(mm, vaddr); >>> p4dp = p4d_alloc(mm, pgdp, vaddr); >>> @@ -1272,11 +1275,11 @@ static int __init debug_vm_pgtable(void) >>> * Page table modifying tests. They need to hold >>> * proper page table lock. >>> */ >>> - >>> - ptep = pte_offset_map_lock(mm, pmdp, vaddr, &ptl); >>> - pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot); >>> - pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); >>> - pte_unmap_unlock(ptep, ptl); >>> + ptl = pte_lockptr(args.mm, args.pmdp); >>> + spin_lock(ptl); >>> + pte_clear_tests(&args); >>> + pte_advanced_tests(&args); >>> + spin_unlock(ptl); >> >> Why pte_offset_map_lock()/pte_unmap_unlock() has been dropped and >> spin_lock()/spin_unlock() sequence has been added ? Please dont >> change the tests in these patches. >> > > The semantics of pte_offset_map_lock() is to grab and take the lock > and return the PTE entry, which is mapped if needed. We already had > the PTE entry tracked by args->ptep in init_args(). So some of the > operations covered by pte_offset_map_lock() isn't needed any more To keep the patch on purpose, please avoid this change here. But if required, you could send a follow up patch later.
