The patch titled
madv_free lazytlb fix
has been added to the -mm tree. Its filename is
madv_free-lazytlb-fix.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: madv_free lazytlb fix
From: Rik van Riel <riel@xxxxxxxxxx>
Jakub found a potential bug, in that I did not use an atomic
operation to clear the page table entries. I've attached a
new patch which simply uses ptep_test_and_clear_dirty/young
to get rid of the dirty and accessed bits.
It uses the same atomic accesses we use elsewhere in the VM
and the code is a line shorter than before.
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff -puN mm/memory.c~madv_free-lazytlb-fix mm/memory.c
--- a/mm/memory.c~madv_free-lazytlb-fix
+++ a/mm/memory.c
@@ -677,11 +677,14 @@ static unsigned long zap_pte_range(struc
remove_exclusive_swap_page(page);
unlock_page(page);
}
- ptep_clear_flush_dirty(vma, addr, pte);
- ptep_clear_flush_young(vma, addr, pte);
+ ptep_test_and_clear_dirty(vma, addr, pte);
+ ptep_test_and_clear_young(vma, addr, pte);
SetPageLazyFree(page);
if (PageActive(page))
deactivate_tail_page(page);
+ /* tlb_remove_page frees it again */
+ get_page(page);
+ tlb_remove_page(tlb, page);
continue;
}
}
_
Patches currently in -mm which might be from riel@xxxxxxxxxx are
mm-madvise-avoid-exclusive-mmap_sem.patch
lazy-freeing-of-memory-through-madv_free.patch
lazy-freeing-of-memory-through-madv_free-fix.patch
lazy-freeing-of-memory-through-madv_free-sparc-fix.patch
madv_free-lazytlb-fix.patch
lazy-freeing-of-memory-through-madv_free-vs-mm-madvise-avoid-exclusive-mmap_sem.patch
restore-madv_dontneed-to-its-original-linux-behaviour.patch
-
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