[PATCH] Suppress split ptlock on arches which may use one page for multiple page tables

Suppress split ptlock on arches which may use one page for multiple page
tables.  Reconsider what better to do (particularly on ppc64) later on.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index 1a4473fcb2ca..ae9ce6b73e8a 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -126,9 +126,11 @@ comment "Memory hotplug is currently incompatible with Software Suspend"
 # Default to 4 for wider testing, though 8 might be more appropriate.
 # ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.
 # PA-RISC's debug spinlock_t is too large for the 32-bit struct page.
+# ARM26 and SPARC32 and PPC64 may use one page for multiple page tables.
 #
 config SPLIT_PTLOCK_CPUS
         int
         default "4096" if ARM && !CPU_CACHE_VIPT
         default "4096" if PARISC && DEBUG_SPINLOCK && !64BIT
+        default "4096" if ARM26 || SPARC32 || PPC64
         default "4"