diff options
| author | Zachary Amsden <zach@vmware.com> | 2006-10-01 08:29:31 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-01 09:39:33 +0200 |
| commit | 9888a1cae3f859db38b9604e3df1c02177161bb0 (patch) | |
| tree | 5954dc5e1a2dc1251a57a41aa15b7776a530f230 | |
| parent | [PATCH] paravirt: remove read hazard from cow (diff) | |
| download | linux-9888a1cae3f859db38b9604e3df1c02177161bb0.tar.xz linux-9888a1cae3f859db38b9604e3df1c02177161bb0.zip | |
[PATCH] paravirt: pte clear not present
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 <zach@vmware.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/asm-generic/pgtable.h | 9 | ||||
| -rw-r--r-- | mm/fremap.c | 2 | ||||
| -rw-r--r-- | mm/memory.c | 2 |
3 files changed, 9 insertions, 4 deletions
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 349260cd86ed..78740716c9e7 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -112,8 +112,13 @@ 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) diff --git a/mm/fremap.c b/mm/fremap.c index aa30618ec6b2..7a9d0f5d246d 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -39,7 +39,7 @@ static int zap_pte(struct mm_struct *mm, struct vm_area_struct *vma, } 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; } diff --git a/mm/memory.c b/mm/memory.c index 7707187484cc..2e754621d333 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -690,7 +690,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, 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); |