The patch titled
powerpc: hugepage BUG fix
has been removed from the -mm tree. Its filename is
powerpc-hugepage-bug-fix.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: powerpc: hugepage BUG fix
From: Adam Litke <agl@xxxxxxxxxx>
On Tue, 2006-08-15 at 08:22 -0700, Dave Hansen wrote:
> kernel BUG in cache_free_debugcheck at mm/slab.c:2748!
Alright, this one is only triggered when slab debugging is enabled. The
slabs are assumed to be aligned on a HUGEPTE_TABLE_SIZE boundary. The free
path makes use of this assumption and uses the lowest nibble to pass around
an index into an array of kmem_cache pointers. With slab debugging turned
on, the slab is still aligned, but the "working" object pointer is not.
This would break the assumption above that a full nibble is available for
the PGF_CACHENUM_MASK.
The following patch reduces PGF_CACHENUM_MASK to cover only the two least
significant bits, which is enough to cover the current number of 4 pgtable
cache types. Then use this constant to mask out the appropriate part of
the huge pte pointer.
Signed-off-by: Adam Litke <agl@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/powerpc/mm/hugetlbpage.c | 2 +-
include/asm-powerpc/pgalloc.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff -puN arch/powerpc/mm/hugetlbpage.c~powerpc-hugepage-bug-fix arch/powerpc/mm/hugetlbpage.c
--- a/arch/powerpc/mm/hugetlbpage.c~powerpc-hugepage-bug-fix
+++ a/arch/powerpc/mm/hugetlbpage.c
@@ -153,7 +153,7 @@ static void free_hugepte_range(struct mm
hpdp->pd = 0;
tlb->need_flush = 1;
pgtable_free_tlb(tlb, pgtable_free_cache(hugepte, HUGEPTE_CACHE_NUM,
- HUGEPTE_TABLE_SIZE-1));
+ PGF_CACHENUM_MASK));
}
#ifdef CONFIG_PPC_64K_PAGES
diff -puN include/asm-powerpc/pgalloc.h~powerpc-hugepage-bug-fix include/asm-powerpc/pgalloc.h
--- a/include/asm-powerpc/pgalloc.h~powerpc-hugepage-bug-fix
+++ a/include/asm-powerpc/pgalloc.h
@@ -117,7 +117,7 @@ static inline void pte_free(struct page
pte_free_kernel(page_address(ptepage));
}
-#define PGF_CACHENUM_MASK 0xf
+#define PGF_CACHENUM_MASK 0x3
typedef struct pgtable_free {
unsigned long val;
_
Patches currently in -mm which might be from agl@xxxxxxxxxx are
origin.patch
-
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