[tip:x86/mm] x86/Kconfig: Deprecate DISCONTIGMEM support for 32-bit x86

[tip-bot for Mike Rapoport]

Commit-ID:  2792107dc3af29ecc1a9b3dc5bc873dac4b61cd6
Gitweb:     https://git.kernel.org/tip/2792107dc3af29ecc1a9b3dc5bc873dac4b61cd6
Author:     Mike Rapoport <rppt@xxxxxxxxxxxxx>
AuthorDate: Wed, 24 Apr 2019 16:24:12 +0300
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 25 Apr 2019 09:02:18 +0200

x86/Kconfig: Deprecate DISCONTIGMEM support for 32-bit x86

Mel Gorman says:

  "32-bit NUMA systems should be non-existent in practice.  The last NUMA
   system I'm aware of that was both NUMA and 32-bit only died somewhere
   between 2004 and 2007. If someone is running a 64-bit capable system in
   32-bit mode with NUMA, they really are just punishing themselves for fun."

Mark DISCONTIGMEM broken for now as suggested by Christoph Hellwig,
and (hopefully) remove it in a couple of releases.

Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Link: http://lkml.kernel.org/r/1556112252-9339-3-git-send-email-rppt@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/Kconfig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0b91756ed980..335d6e37f151 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1606,8 +1606,9 @@ config ARCH_FLATMEM_ENABLE
 	depends on X86_32 && !NUMA
 
 config ARCH_DISCONTIGMEM_ENABLE
-	def_bool y
+	def_bool n
 	depends on NUMA && X86_32
+	depends on BROKEN
 
 config ARCH_SPARSEMEM_ENABLE
 	def_bool y