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i386 mm: use pte_update() in ptep_test_and_clear_dirty()

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It is not safe to use pte_update_defer() in ptep_test_and_clear_young():
its only user, /proc/<pid>/clear_refs, drops pte lock before flushing TLB.
Use the safe though less efficient pte_update() paravirtop in its place.
Likewise in ptep_test_and_clear_dirty(), though that has no current use.

These are macros (header file dependency stops them from becoming inline
functions), so be more liberal with the underscores and parentheses.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Hugh Dickins 2007-06-16 10:15:59 -07:00 committed by Linus Torvalds
parent 30475cc12a
commit d6f8bb1310
1 changed files with 14 additions and 12 deletions
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26
include/asm-i386/pgtable.h
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@ -295,22 +295,24 @@ do { \
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
#define ptep_test_and_clear_dirty(vma, addr, ptep) ({ \
int ret = 0; \
if (pte_dirty(*ptep)) \
ret = test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte_low); \
if (ret) \
pte_update_defer(vma->vm_mm, addr, ptep); \
ret; \
int __ret = 0; \
if (pte_dirty(*(ptep))) \
__ret = test_and_clear_bit(_PAGE_BIT_DIRTY, \
&(ptep)->pte_low); \
if (__ret) \
pte_update((vma)->vm_mm, addr, ptep); \
__ret; \
})
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define ptep_test_and_clear_young(vma, addr, ptep) ({ \
int ret = 0; \
if (pte_young(*ptep)) \
ret = test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte_low); \
if (ret) \
pte_update_defer(vma->vm_mm, addr, ptep); \
ret; \
int __ret = 0; \
if (pte_young(*(ptep))) \
__ret = test_and_clear_bit(_PAGE_BIT_ACCESSED, \
&(ptep)->pte_low); \
if (__ret) \
pte_update((vma)->vm_mm, addr, ptep); \
__ret; \
})
/*