diff options
author | Zachary Amsden <zach@vmware.com> | 2006-10-01 02:29:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-01 03:39:34 -0400 |
commit | d6d861e3c963b4077c83e078e3e300c4b81f93e7 (patch) | |
tree | 842071ac905575aa0ea8bedd3a1ac5db29416bcf /include/asm-i386/pgtable-2level.h | |
parent | 23002d88be309a7c78db69363c9d933a29a3b0bb (diff) |
[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 <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-i386/pgtable-2level.h')
-rw-r--r-- | include/asm-i386/pgtable-2level.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/asm-i386/pgtable-2level.h b/include/asm-i386/pgtable-2level.h index 201c86a6711e..8d8d3b9ecdb0 100644 --- a/include/asm-i386/pgtable-2level.h +++ b/include/asm-i386/pgtable-2level.h | |||
@@ -16,6 +16,7 @@ | |||
16 | #define set_pte(pteptr, pteval) (*(pteptr) = pteval) | 16 | #define set_pte(pteptr, pteval) (*(pteptr) = pteval) |
17 | #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval) | 17 | #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval) |
18 | #define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval) | 18 | #define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval) |
19 | #define set_pte_present(mm,addr,ptep,pteval) set_pte_at(mm,addr,ptep,pteval) | ||
19 | #define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval)) | 20 | #define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval)) |
20 | 21 | ||
21 | #define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0) | 22 | #define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0) |