[PATCH] mm/thp: Make ARCH_ENABLE_SPLIT_PMD_PTLOCK dependent on PGTABLE_LEVELS > 2

From: Anshuman Khandual <anshuman.khandual@arm.com>
To: linux-mm@kvack.org, akpm@linux-foundation.org
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	x86@kernel.org, linux-s390@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] mm/thp: Make ARCH_ENABLE_SPLIT_PMD_PTLOCK dependent on PGTABLE_LEVELS > 2
Date: Mon, 10 May 2021 10:05:45 +0530	[thread overview]
Message-ID: <1620621345-29176-1-git-send-email-anshuman.khandual@arm.com> (raw)

ARCH_ENABLE_SPLIT_PMD_PTLOCK is irrelevant unless there are two page table
levels including PMD (also per Documentation/vm/split_page_table_lock.rst).
Make this dependency explicit on remaining platforms i.e x86 and s390 where
ARCH_ENABLE_SPLIT_PMD_PTLOCK is subscribed.

Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: x86@kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/s390/Kconfig | 2 +-
 arch/x86/Kconfig  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index b4c7c34069f8..fcc1ea339a9d 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -62,7 +62,7 @@ config S390
 	select ARCH_BINFMT_ELF_STATE
 	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
 	select ARCH_ENABLE_MEMORY_HOTREMOVE
-	select ARCH_ENABLE_SPLIT_PMD_PTLOCK
+	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
 	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DEBUG_WX
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0045e1b44190..ec9e9d3d7e3f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -63,7 +63,7 @@ config X86
 	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
 	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 || (X86_32 && HIGHMEM)
 	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
-	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if X86_64 || X86_PAE
+	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
 	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
 	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
 	select ARCH_HAS_CACHE_LINE_SIZE
-- 
2.20.1

