x86: require x86-64 for automatic NUMA balancing

32-bit support for NUMA is an oddity on its own but with automatic NUMA
balancing on top there is a reasonable risk that the CPUPID information
cannot be stored in the page flags.  This patch removes support for
automatic NUMA support on 32-bit x86.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 25d2c6f7325e8d64133100d651661af713f6563a..eb3b7244ad33f54c49edf8097a6b52618c9b018c 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -26,7 +26,7 @@ config X86
        select ARCH_MIGHT_HAVE_PC_SERIO
        select HAVE_AOUT if X86_32
        select HAVE_UNSTABLE_SCHED_CLOCK
-       select ARCH_SUPPORTS_NUMA_BALANCING
+       select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
        select ARCH_SUPPORTS_INT128 if X86_64
        select ARCH_WANTS_PROT_NUMA_PROT_NONE
        select HAVE_IDE