linux-kernel - [PATCH v4 8/8] mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE

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Message-ID: <83b034810935a9ff18e425b085e065bb0acb28f3.1769515122.git.zhengqi.arch@bytedance.com>
Date: Tue, 27 Jan 2026 20:13:01 +0800
From: Qi Zheng <qi.zheng@...ux.dev>
To: david@...nel.org,
	andreas@...sler.com,
	richard.weiyang@...il.com,
	will@...nel.org,
	peterz@...radead.org,
	aneesh.kumar@...nel.org,
	npiggin@...il.com,
	dev.jain@....com,
	ioworker0@...il.com,
	linmag7@...il.com,
	akpm@...ux-foundation.org
Cc: linux-arch@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	linux-alpha@...r.kernel.org,
	loongarch@...ts.linux.dev,
	linux-mips@...r.kernel.org,
	linux-parisc@...r.kernel.org,
	linux-um@...ts.infradead.org,
	sparclinux@...r.kernel.org,
	Qi Zheng <zhengqi.arch@...edance.com>
Subject: [PATCH v4 8/8] mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE

From: Qi Zheng <zhengqi.arch@...edance.com>

The PT_RECLAIM can work on all architectures that support
MMU_GATHER_RCU_TABLE_FREE, except for those that have selected
HAVE_ARCH_TLB_REMOVE_TABLE,so make PT_RECLAIM depends on
MMU_GATHER_RCU_TABLE_FREE && !HAVE_ARCH_TLB_REMOVE_TABLE.

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

Signed-off-by: Qi Zheng <zhengqi.arch@...edance.com>
Acked-by: David Hildenbrand (Red Hat) <david@...nel.org>
---
 arch/x86/Kconfig | 1 -
 mm/Kconfig       | 9 ++-------
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 80527299f859a..0d22da56a71b0 100644
--- a/arch/x86/Kconfig
+++ b/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
diff --git a/mm/Kconfig b/mm/Kconfig
index 456e9eaedca39..1f3109b164d86 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1454,14 +1454,9 @@ config ARCH_HAS_USER_SHADOW_STACK
 config HAVE_ARCH_TLB_REMOVE_TABLE
 	def_bool n
 
-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 && !HAVE_ARCH_TLB_REMOVE_TABLE
 	help
 	  Try to reclaim empty user page table pages in paths other than munmap
 	  and exit_mmap path.
-- 
2.20.1