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authorJeremy Fitzhardinge <jeremy@goop.org>2008-02-04 16:48:02 +0100
committerIngo Molnar <mingo@elte.hu>2008-02-04 16:48:02 +0100
commita67ad9c9f82342a9b320fdad204a490727ef4a18 (patch)
tree47117746d64a3255e35fda69e8127d64e35fe122 /include/asm-x86
parente618c9579c745742c422b7c3de1f802aa67e6110 (diff)
downloadop-kernel-dev-a67ad9c9f82342a9b320fdad204a490727ef4a18.zip
op-kernel-dev-a67ad9c9f82342a9b320fdad204a490727ef4a18.tar.gz
x86: revert "defer cr3 reload when doing pud_clear()"
Revert "defer cr3 reload when doing pud_clear()" since I'm going to replace it. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/asm-x86')
-rw-r--r--include/asm-x86/pgtable-3level.h21
1 files changed, 6 insertions, 15 deletions
diff --git a/include/asm-x86/pgtable-3level.h b/include/asm-x86/pgtable-3level.h
index a195c3e..ed4c6f0 100644
--- a/include/asm-x86/pgtable-3level.h
+++ b/include/asm-x86/pgtable-3level.h
@@ -96,23 +96,14 @@ static inline void pud_clear(pud_t *pudp)
set_pud(pudp, __pud(0));
/*
- * In principle we need to do a cr3 reload here to make sure
- * the processor recognizes the changed pgd. In practice, all
- * the places where pud_clear() gets called are followed by
- * full tlb flushes anyway, so we can defer the cost here.
+ * Pentium-II erratum A13: in PAE mode we explicitly have to flush
+ * the TLB via cr3 if the top-level pgd is changed...
*
- * Specifically:
- *
- * mm/memory.c:free_pmd_range() - immediately after the
- * pud_clear() it does a pmd_free_tlb(). We change the
- * mmu_gather structure to do a full tlb flush (which has the
- * effect of reloading cr3) when the pagetable free is
- * complete.
- *
- * arch/x86/mm/hugetlbpage.c:huge_pmd_unshare() - the call to
- * this is followed by a flush_tlb_range, which on x86 does a
- * full tlb flush.
+ * XXX I don't think we need to worry about this here, since
+ * when clearing the pud, the calling code needs to flush the
+ * tlb anyway. But do it now for safety's sake. - jsgf
*/
+ write_cr3(read_cr3());
}
#define pud_page(pud) \
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