linux-kernel - [PATCH V2] mm/thp: Make ARCH_ENABLE_SPLIT_PMD_PTLOCK dependent on PGTABLE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <1622013501-20409-1-git-send-email-anshuman.khandual@arm.com>
Date:   Wed, 26 May 2021 12:48:21 +0530
From:   Anshuman Khandual <anshuman.khandual@....com>
To:     linux-mm@...ck.org, akpm@...ux-foundation.org
Cc:     Anshuman Khandual <anshuman.khandual@....com>,
        Heiko Carstens <hca@...ux.ibm.com>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, x86@...nel.org,
        linux-s390@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH V2] mm/thp: Make ARCH_ENABLE_SPLIT_PMD_PTLOCK dependent on PGTABLE_LEVELS > 2

ARCH_ENABLE_SPLIT_PMD_PTLOCK is irrelevant unless there are more than 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@...ux.ibm.com>
Cc: Vasily Gorbik <gor@...ux.ibm.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: x86@...nel.org
Cc: linux-s390@...r.kernel.org
Cc: linux-mm@...ck.org
Cc: linux-kernel@...r.kernel.org
Acked-by: Gerald Schaefer <gerald.schaefer@...ux.ibm.com> # s390
Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>
---
Changes in V2:

- Updated the commit message per Gerald

Changes in V1:

https://lore.kernel.org/linux-mm/1620621345-29176-1-git-send-email-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