Small nit for the subject line.
s/Remove unused code/Remove unused page table debug elements/
On 7/19/21 6:36 PM, Gavin Shan wrote:
> The variables used by old implementation isn't needed as we switched
> to "struct pgtable_debug_args". Lets remove them and related code in
> debug_vm_pgtable().
>
> Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
> ---
> mm/debug_vm_pgtable.c | 54 -------------------------------------------
> 1 file changed, 54 deletions(-)
>
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 5ebacc940b68..4f7bf1c9724a 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -1124,14 +1124,6 @@ static int __init init_args(struct pgtable_debug_args *args)
> static int __init debug_vm_pgtable(void)
> {
> struct pgtable_debug_args args;
> - struct vm_area_struct *vma;
> - struct mm_struct *mm;
> - pgd_t *pgdp;
> - p4d_t *p4dp;
> - pud_t *pudp;
> - pmd_t *pmdp, *saved_pmdp, pmd;
> - pgtable_t saved_ptep;
> - unsigned long vaddr;
> spinlock_t *ptl = NULL;
> int idx, ret;
>
> @@ -1140,41 +1132,6 @@ static int __init debug_vm_pgtable(void)
> if (ret)
> return ret;
>
> - vaddr = get_random_vaddr();
> - mm = mm_alloc();
> - if (!mm) {
> - pr_err("mm_struct allocation failed\n");
> - return 1;
> - }
> -
> - vma = vm_area_alloc(mm);
> - if (!vma) {
> - pr_err("vma allocation failed\n");
> - return 1;
> - }
> -
> - pgdp = pgd_offset(mm, vaddr);
> - p4dp = p4d_alloc(mm, pgdp, vaddr);
> - pudp = pud_alloc(mm, p4dp, vaddr);
> - pmdp = pmd_alloc(mm, pudp, vaddr);
> - /*
> - * Allocate pgtable_t
> - */
> - if (pte_alloc(mm, pmdp)) {
> - pr_err("pgtable allocation failed\n");
> - return 1;
> - }
> -
> - /*
> - * Save all the page table page addresses as the page table
> - * entries will be used for testing with random or garbage
> - * values. These saved addresses will be used for freeing
> - * page table pages.
> - */
Please move this comment as is to the right place inside init_args()
in the first patch itself. If possible all comments should be moved
during the first patch and just the code gets dropped here.
> - pmd = READ_ONCE(*pmdp);
> - saved_pmdp = pmd_offset(pudp, 0UL);
> - saved_ptep = pmd_pgtable(pmd);
> -
> /*
> * Iterate over the protection_map[] to make sure that all
> * the basic page table transformation validations just hold
> @@ -1256,17 +1213,6 @@ static int __init debug_vm_pgtable(void)
> pgd_populate_tests(&args);
> spin_unlock(&(args.mm->page_table_lock));
>
> - p4d_free(mm, p4d_offset(pgdp, 0UL));
> - pud_free(mm, pud_offset(p4dp, 0UL));
> - pmd_free(mm, saved_pmdp);
> - pte_free(mm, saved_ptep);
> -
> - vm_area_free(vma);
> - mm_dec_nr_puds(mm);
> - mm_dec_nr_pmds(mm);
> - mm_dec_nr_ptes(mm);
> - mmdrop(mm);
> -
> destroy_args(&args);
> return 0;
> }
>
