+ mm-make-pt_reclaim-depends-on-mmu_gather_rcu_table_free.patch added to mm-new branch

+ mm-make-pt_reclaim-depends-on-mmu_gather_rcu_table_free.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE
has been added to the -mm mm-new branch.  Its filename is
     mm-make-pt_reclaim-depends-on-mmu_gather_rcu_table_free.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-make-pt_reclaim-depends-on-mmu_gather_rcu_table_free.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

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------------------------------------------------------
From: Qi Zheng <zhengqi.arch@bytedance.com>
Subject: mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE
Date: Wed, 17 Dec 2025 17:45:48 +0800

PT_RECLAIM can work on all architectures that support
MMU_GATHER_RCU_TABLE_FREE, so make PT_RECLAIM depends on
MMU_GATHER_RCU_TABLE_FREE.

BTW, change PT_RECLAIM to be enabled by default, since nobody should want
to turn it off.

Link: https://lkml.kernel.org/r/ac2bdb2a66da1edb24f60d1da1099e2a0b734880.1765963770.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/Kconfig |    1 -
 mm/Kconfig       |    9 ++-------
 2 files changed, 2 insertions(+), 8 deletions(-)

--- a/arch/x86/Kconfig~mm-make-pt_reclaim-depends-on-mmu_gather_rcu_table_free
+++ a/arch/x86/Kconfig
@@ -331,7 +331,6 @@ config X86
 	select FUNCTION_ALIGNMENT_4B
 	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
 	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
-	select ARCH_SUPPORTS_PT_RECLAIM		if X86_64
 	select ARCH_SUPPORTS_SCHED_SMT		if SMP
 	select SCHED_SMT			if SMP
 	select ARCH_SUPPORTS_SCHED_CLUSTER	if SMP
--- a/mm/Kconfig~mm-make-pt_reclaim-depends-on-mmu_gather_rcu_table_free
+++ a/mm/Kconfig
@@ -1447,14 +1447,9 @@ config ARCH_HAS_USER_SHADOW_STACK
 	  The architecture has hardware support for userspace shadow call
           stacks (eg, x86 CET, arm64 GCS or RISC-V Zicfiss).
 
-config ARCH_SUPPORTS_PT_RECLAIM
-	def_bool n
-
 config PT_RECLAIM
-	bool "reclaim empty user page table pages"
-	default y
-	depends on ARCH_SUPPORTS_PT_RECLAIM && MMU && SMP
-	select MMU_GATHER_RCU_TABLE_FREE
+	def_bool y
+	depends on MMU_GATHER_RCU_TABLE_FREE
 	help
 	  Try to reclaim empty user page table pages in paths other than munmap
 	  and exit_mmap path.
_

Patches currently in -mm which might be from zhengqi.arch@bytedance.com are

mm-change-mm-pt_reclaimc-to-use-asm-tlbh-instead-of-asm-generic-tlbh.patch
alpha-mm-enable-mmu_gather_rcu_table_free.patch
loongarch-mm-enable-mmu_gather_rcu_table_free.patch
mips-mm-enable-mmu_gather_rcu_table_free.patch
parisc-mm-enable-mmu_gather_rcu_table_free.patch
um-mm-enable-mmu_gather_rcu_table_free.patch
mm-make-pt_reclaim-depends-on-mmu_gather_rcu_table_free.patch