Commit Graph

5 Commits

Author SHA1 Message Date
Adam Litke c9169f8747 [POWERPC] hugepage BUG fix
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@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-08-24 10:07:23 +10:00
David Gibson f10a04c034 [PATCH] powerpc: Fix pagetable bloat for hugepages
At present, ARCH=powerpc kernels can waste considerable space in
pagetables when making large hugepage mappings.  Hugepage PTEs go in
PMD pages, but each PMD page maps 256M and so contains only 16
hugepage PTEs (128 bytes of data), but takes up a 1024 byte
allocation.  With CONFIG_PPC_64K_PAGES enabled (64k base page size),
the situation is worse.  Now hugepage PTEs are at the PTE page level
(also mapping 256M), so we store 16 hugepage PTEs in a 64k allocation.

The PowerPC MMU already means that any 256M region is either all
hugepage, or all normal pages.  Thus, with some care, we can use a
different allocation for the hugepage PTE tables and only allocate the
128 bytes necessary.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-28 15:02:51 +10:00
David Gibson 200a4552af [PATCH] powerpc: Fix accidentally-working typo in __pud_free_tlb
One of the parameters to the __pud_free_tlb() macro for powerpc is
incorrect (see patch) .  We get away with it by accident, because the one
place the macro is called, the second parameter is a variable named "pud".

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17 13:59:27 -08:00
Arnd Bergmann 88ced03149 [PATCH] powerpc: sanitize header files for user space includes
include/asm-ppc/ had #ifdef __KERNEL__ in all header files that
are not meant for use by user space, include/asm-powerpc does
not have this yet.

This patch gets us a lot closer there. There are a few cases
where I was not sure, so I left them out. I have verified
that no CONFIG_* symbols are used outside of __KERNEL__
any more and that there are no obvious compile errors when
including any of the headers in user space libraries.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09 15:13:08 +11:00
Paul Mackerras 047ea78465 powerpc: Trivially merge several headers from asm-ppc64 to asm-powerpc
For these, I have just done the lame-o merge where the file ends up
looking like:

	#ifndef CONFIG_PPC64
	#include <asm-ppc/foo.h>
	#else
	... contents from asm-ppc64/foo.h
	#endif

so nothing has changed, really, except that we reduce include/asm-ppc64
a bit more.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-19 20:17:32 +11:00