Commit-ID: 154e911b453560aa1e6e11d47e5f95289817b932
Gitweb: http://git.kernel.org/tip/154e911b453560aa1e6e11d47e5f95289817b932
Author: Rik van Riel <riel@xxxxxxxxxx>
AuthorDate: Tue, 9 Oct 2012 15:31:59 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 12 Oct 2012 12:07:16 +0200
mm: Only flush the TLB when clearing an accessible pte
If ptep_clear_flush() is called to clear a page table entry that is
accessible anyway by the CPU, eg. a _PAGE_PROTNONE page table entry,
there is no need to flush the TLB on remote CPUs.
Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-vm3rkzevahelwhejx5uwm8ex@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
mm/pgtable-generic.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 74c0dda..0996d34 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -88,7 +88,8 @@ pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
{
pte_t pte;
pte = ptep_get_and_clear((vma)->vm_mm, address, ptep);
- flush_tlb_page(vma, address);
+ if (pte_accessible(pte))
+ flush_tlb_page(vma, address);
return pte;
}
#endif
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