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| author | Zachary Amsden <zach@vmware.com> | 2006-10-01 06:29:36 (GMT) |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-01 07:39:34 (GMT) |
| commit | d6d861e3c963b4077c83e078e3e300c4b81f93e7 (patch) | |
| tree | 842071ac905575aa0ea8bedd3a1ac5db29416bcf /include/asm-i386/pgtable.h | |
| parent | 23002d88be309a7c78db69363c9d933a29a3b0bb (diff) | |
| download | linux-d6d861e3c963b4077c83e078e3e300c4b81f93e7.tar.xz | |
[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.h')
| -rw-r--r-- | include/asm-i386/pgtable.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h index ee9696d..8cb708a 100644 --- a/include/asm-i386/pgtable.h +++ b/include/asm-i386/pgtable.h @@ -269,6 +269,17 @@ do { \ #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG +/* + * Rules for using ptep_establish: the pte MUST be a user pte, and + * must be a present->present transition. + */ +#define __HAVE_ARCH_PTEP_ESTABLISH +#define ptep_establish(vma, address, ptep, pteval) \ +do { \ + set_pte_present((vma)->vm_mm, address, ptep, pteval); \ + flush_tlb_page(vma, address); \ +} while (0) + #define __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH #define ptep_clear_flush_dirty(vma, address, ptep) \ ({ \ |