[PATCH 2/9] 00mm2 pte clear not present.patch
DORMANTno replies
From: Zachary Amsden <hidden>
Date: 2006-08-11 09:29:52
Also in:
linux-mm, lkml
Change pte_clear_full to a more appropriately named pte_clear_not_present, allowing optimizations when not-present mapping changes need not be reflected in the hardware TLB for protected page table modes. There is also another case that can use it in the fremap code. Signed-off-by: Zachary Amsden <redacted> Signed-off-by: Jeremy Fitzhardinge <redacted> --- include/asm-generic/pgtable.h | 4 ++-- mm/fremap.c | 2 +- mm/memory.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) ===================================================================
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h@@ -110,8 +110,13 @@ do { \ }) #endif -#ifndef __HAVE_ARCH_PTE_CLEAR_FULL -#define pte_clear_full(__mm, __address, __ptep, __full) \ +/* + * Some architectures may be able to avoid expensive synchronization + * primitives when modifications are made to PTE's which are already + * not present, or in the process of an address space destruction. + */ +#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL +#define pte_clear_not_present_full(__mm, __address, __ptep, __full) \ do { \ pte_clear((__mm), (__address), (__ptep)); \ } while (0)
===================================================================
--- a/mm/fremap.c
+++ b/mm/fremap.c@@ -39,7 +39,7 @@ static int zap_pte(struct mm_struct *mm, } else { if (!pte_file(pte)) free_swap_and_cache(pte_to_swp_entry(pte)); - pte_clear(mm, addr, ptep); + pte_clear_not_present_full(mm, addr, ptep, 0); } return !!page; }
===================================================================
--- a/mm/memory.c
+++ b/mm/memory.c@@ -689,7 +689,7 @@ static unsigned long zap_pte_range(struc continue; if (!pte_file(ptent)) free_swap_and_cache(pte_to_swp_entry(ptent)); - pte_clear_full(mm, addr, pte, tlb->fullmm); + pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0)); add_mm_rss(mm, file_rss, anon_rss);