The patch titled
fix NUMA interleaving for huge pages
has been added to the -mm tree. Its filename is
fix-numa-interleaving-for-huge-pages.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: fix NUMA interleaving for huge pages
From: Nishanth Aravamudan <nacc@xxxxxxxxxx>
Since vma->vm_pgoff is in units of smallpages, VMAs for huge pages have the
lower HPAGE_SHIFT - PAGE_SHIFT bits always cleared, which results in badd
offsets to the interleave functions. Take this difference from small pages
into account when calculating the offset. This does add a 0-bit shift into
the small-page path (via alloc_page_vma()), but I think that is negligible.
Also add a BUG_ON to prevent the offset from growing due to a negative
right-shift, which probably shouldn't be allowed anyways.
Tested on an 8-memory node ppc64 NUMA box and got the interleaving I
expected.
Signed-off-by: Nishanth Aravamudan <nacc@xxxxxxxxxx>
Signed-off-by: Adam Litke <agl@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxx>
Cc: Christoph Lameter <clameter@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/mempolicy.c | 10 +++++++++-
1 files changed, 9 insertions(+), 1 deletion(-)
diff -puN mm/mempolicy.c~fix-numa-interleaving-for-huge-pages mm/mempolicy.c
--- a/mm/mempolicy.c~fix-numa-interleaving-for-huge-pages
+++ a/mm/mempolicy.c
@@ -1181,7 +1181,15 @@ static inline unsigned interleave_nid(st
if (vma) {
unsigned long off;
- off = vma->vm_pgoff;
+ /*
+ * for small pages, there is no difference between
+ * shift and PAGE_SHIFT, so the bit-shift is safe.
+ * for huge pages, since vm_pgoff is in units of small
+ * pages, we need to shift off the always 0 bits to get
+ * a useful offset.
+ */
+ BUG_ON(shift < PAGE_SHIFT);
+ off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
off += (addr - vma->vm_start) >> shift;
return offset_il_node(pol, vma, off);
} else
_
Patches currently in -mm which might be from nacc@xxxxxxxxxx are
fix-numa-interleaving-for-huge-pages.patch
-
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