[PATCH] mm: Make SPLIT_PTE_PTLOCKS depend on the existence of NR_CPUS

From: Guenter Roeck
Date: Mon Sep 23 2024 - 10:25:43 EST


SPLIT_PTE_PTLOCKS already depends on "NR_CPUS >= 4", but that evaluates
to true if there is no NR_CPUS configuration option (such as for m68k).
This results in CONFIG_SPLIT_PTE_PTLOCKS=y for mac_defconfig.
This in turn causes the m68k "q800" machine to crash in qemu.

Adding an explicit dependency on the existence of NR_CPUS fixes the
problem.

Fixes: 394290cba966 ("mm: turn USE_SPLIT_PTE_PTLOCKS / USE_SPLIT_PTE_PTLOCKS into Kconfig options")
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
mm/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/Kconfig b/mm/Kconfig
index 09aebca1cae3..20fe60389cf5 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -595,7 +595,7 @@ config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
config SPLIT_PTE_PTLOCKS
def_bool y
depends on MMU
- depends on NR_CPUS >= 4
+ depends on NR_CPUS && NR_CPUS >= 4
depends on !ARM || CPU_CACHE_VIPT
depends on !PARISC || PA20
depends on !SPARC32
--
2.45.2