3.16.59-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Naoya Horiguchi <n-horigu...@ah.jp.nec.com>
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 <n-horigu...@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
Cc: Andrea Arcangeli <aarca...@redhat.com>
Cc: Cyrill Gorcunov <gorcu...@openvz.org>
Cc: Dave Hansen <dave.han...@intel.com>
Cc: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
Cc: Pavel Emelyanov <xe...@parallels.com>
Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
[bwh: Backported to 3.16 as dependency of L1TF mitigation]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
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;
