From d6d861e3c963b4077c83e078e3e300c4b81f93e7 Mon Sep 17 00:00:00 2001 From: Zachary Amsden Date: Sat, 30 Sep 2006 23:29:36 -0700 Subject: [PATCH] paravirt: optimize ptep establish for pae The ptep_establish macro is only used on user-level PTEs, for P->P mapping changes. Since these always happen under protection of the pagetable lock, the strong synchronization of a 64-bit cmpxchg is not needed, in fact, not even a lock prefix needs to be used. We can simply instead clear the P-bit, followed by a normal set. The write ordering is still important to avoid the possibility of the TLB snooping a partially written PTE and getting a bad mapping installed. Signed-off-by: Zachary Amsden Cc: Rusty Russell Cc: Jeremy Fitzhardinge Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-i386/pgtable-2level.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/asm-i386/pgtable-2level.h') diff --git a/include/asm-i386/pgtable-2level.h b/include/asm-i386/pgtable-2level.h index 201c86a6711..8d8d3b9ecdb 100644 --- a/include/asm-i386/pgtable-2level.h +++ b/include/asm-i386/pgtable-2level.h @@ -16,6 +16,7 @@ #define set_pte(pteptr, pteval) (*(pteptr) = pteval) #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval) #define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval) +#define set_pte_present(mm,addr,ptep,pteval) set_pte_at(mm,addr,ptep,pteval) #define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval)) #define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0) -- cgit v1.2.3