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| author | Zachary Amsden <zach@vmware.com> | 2005-09-03 15:55:06 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@evo.osdl.org> | 2005-09-05 00:05:48 -0700 |
| commit | 61e06037e764337da39dff307cbcdbe9cf288349 (patch) | |
| tree | e9719788c751c1d4a437c98056e2ddd7e34d5dfa | |
| parent | a600388d28419305aad3c4c0af52c223cf6fa0af (diff) | |
| download | op-kernel-dev-61e06037e764337da39dff307cbcdbe9cf288349.zip op-kernel-dev-61e06037e764337da39dff307cbcdbe9cf288349.tar.gz | |
[PATCH] x86_64: avoid some atomic operations during address space destruction
Any architecture that has hardware updated A/D bits that require
synchronization against other processors during PTE operations can benefit
from doing non-atomic PTE updates during address space destruction.
Originally done on i386, now ported to x86_64.
Doing a read/write pair instead of an xchg() operation saves the implicit
lock, which turns out to be a big win on 32-bit (esp w PAE).
Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/asm-x86_64/pgtable.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/asm-x86_64/pgtable.h b/include/asm-x86_64/pgtable.h index a1ada85..5e0f2fd 100644 --- a/include/asm-x86_64/pgtable.h +++ b/include/asm-x86_64/pgtable.h @@ -104,6 +104,19 @@ extern inline void pgd_clear (pgd_t * pgd) ((unsigned long) __va(pud_val(pud) & PHYSICAL_PAGE_MASK)) #define ptep_get_and_clear(mm,addr,xp) __pte(xchg(&(xp)->pte, 0)) + +static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long addr, pte_t *ptep, int full) +{ + pte_t pte; + if (full) { + pte = *ptep; + *ptep = __pte(0); + } else { + pte = ptep_get_and_clear(mm, addr, ptep); + } + return pte; +} + #define pte_same(a, b) ((a).pte == (b).pte) #define PMD_SIZE (1UL << PMD_SHIFT) @@ -434,6 +447,7 @@ extern int kern_addr_valid(unsigned long addr); #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY #define __HAVE_ARCH_PTEP_GET_AND_CLEAR +#define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL #define __HAVE_ARCH_PTEP_SET_WRPROTECT #define __HAVE_ARCH_PTE_SAME #include <asm-generic/pgtable.h> |
