summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMel Gorman <mgorman@suse.de>2013-12-18 17:08:34 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-12-18 19:04:51 -0800
commit67f87463d3a3362424efcbe8b40e4772fd34fc61 (patch)
treeb1c6f03215b39dc696c8801bc91310e0aa9ffd47
parentf714f4f20e59ea6eea264a86b9a51fd51b88fc54 (diff)
downloadop-kernel-dev-67f87463d3a3362424efcbe8b40e4772fd34fc61.zip
op-kernel-dev-67f87463d3a3362424efcbe8b40e4772fd34fc61.tar.gz
mm: clear pmd_numa before invalidating
On x86, PMD entries are similar to _PAGE_PROTNONE protection and are handled as NUMA hinting faults. The following two page table protection bits are what defines them _PAGE_NUMA:set _PAGE_PRESENT:clear A PMD is considered present if any of the _PAGE_PRESENT, _PAGE_PROTNONE, _PAGE_PSE or _PAGE_NUMA bits are set. If pmdp_invalidate encounters a pmd_numa, it clears the present bit leaving _PAGE_NUMA which will be considered not present by the CPU but present by pmd_present. The existing caller of pmdp_invalidate should handle it but it's an inconsistent state for a PMD. This patch keeps the state consistent when calling pmdp_invalidate. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/pgtable-generic.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index cbb3854..e84cad2 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -191,6 +191,9 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
+ pmd_t entry = *pmdp;
+ if (pmd_numa(entry))
+ entry = pmd_mknonnuma(entry);
set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(*pmdp));
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
}
OpenPOWER on IntegriCloud