[PATCH 3.16 104/131] mm/pagewalk: remove pgd_entry() and pud_entry()
From: Ben Hutchings <hidden>
Date: 2018-09-29 21:56:23
Also in:
lkml
3.16.59-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Naoya Horiguchi <redacted> commit 0b1fbfe50006c41014cc25660c0e735d21c34939 upstream. Currently no user of page table walker sets ->pgd_entry() or ->pud_entry(), so checking their existence in each loop is just wasting CPU cycle. So let's remove it to reduce overhead. Signed-off-by: Naoya Horiguchi <redacted> Acked-by: Kirill A. Shutemov <redacted> Cc: Andrea Arcangeli <redacted> Cc: Cyrill Gorcunov <redacted> Cc: Dave Hansen <redacted> Cc: Kirill A. Shutemov <redacted> Cc: Pavel Emelyanov <redacted> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.16 as dependency of L1TF mitigation] Signed-off-by: Ben Hutchings <redacted> --- include/linux/mm.h | 6 ------ mm/pagewalk.c | 9 ++------- 2 files changed, 2 insertions(+), 13 deletions(-)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -1114,8 +1114,6 @@ void unmap_vmas(struct mmu_gather *tlb, /** * mm_walk - callbacks for walk_page_range - * @pgd_entry: if set, called for each non-empty PGD (top-level) entry - * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry * this handler is required to be able to handle * pmd_trans_huge() pmds. They may simply choose to
@@ -1129,10 +1127,6 @@ void unmap_vmas(struct mmu_gather *tlb, * (see walk_page_range for more details) */ struct mm_walk { - int (*pgd_entry)(pgd_t *pgd, unsigned long addr, - unsigned long next, struct mm_walk *walk); - int (*pud_entry)(pud_t *pud, unsigned long addr, - unsigned long next, struct mm_walk *walk); int (*pmd_entry)(pmd_t *pmd, unsigned long addr, unsigned long next, struct mm_walk *walk); int (*pte_entry)(pte_t *pte, unsigned long addr, --- a/mm/pagewalk.c +++ b/mm/pagewalk.c
@@ -86,9 +86,7 @@ static int walk_pud_range(pgd_t *pgd, un break; continue; } - if (walk->pud_entry) - err = walk->pud_entry(pud, addr, next, walk); - if (!err && (walk->pmd_entry || walk->pte_entry)) + if (walk->pmd_entry || walk->pte_entry) err = walk_pmd_range(pud, addr, next, walk); if (err) break;
@@ -237,10 +235,7 @@ int walk_page_range(unsigned long addr, pgd++; continue; } - if (walk->pgd_entry) - err = walk->pgd_entry(pgd, addr, next, walk); - if (!err && - (walk->pud_entry || walk->pmd_entry || walk->pte_entry)) + if (walk->pmd_entry || walk->pte_entry) err = walk_pud_range(pgd, addr, next, walk); if (err) break;