mm: x86 pgtable: require X86_64 for soft-dirty tracker
Tracking dirty status on 2 level pages requires very ugly macros and
taking into account how old the machines who can operate without PAE
mode only are, lets drop soft dirty tracker from them for code
simplicity (note I can't drop all the macros from 2 level pages by now
since _PAGE_BIT_PROTNONE and _PAGE_BIT_FILE are still used even without
tracker).
Linus proposed to completely rip off softdirty support on x86-32 (even
with PAE) and since for CRIU we're not planning to support native x86-32
mode, lets do that.
(Softdirty tracker is relatively new feature which is mostly used by
CRIU so I don't expect if such API change would cause problems for
userspace).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4a0137f..69086a3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -105,7 +105,7 @@
select HAVE_ARCH_SECCOMP_FILTER
select BUILDTIME_EXTABLE_SORT
select GENERIC_CMOS_UPDATE
- select HAVE_ARCH_SOFT_DIRTY
+ select HAVE_ARCH_SOFT_DIRTY if X86_64
select CLOCKSOURCE_WATCHDOG
select GENERIC_CLOCKEVENTS
select ARCH_CLOCKSOURCE_DATA