linux-kernel - [PATCH 0/7] enable PT_RECLAIM on all 64-bit architectures

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Message-ID: <cover.1763117269.git.zhengqi.arch@bytedance.com>
Date: Fri, 14 Nov 2025 19:11:14 +0800
From: Qi Zheng <qi.zheng@...ux.dev>
To: will@...nel.org,
	aneesh.kumar@...nel.org,
	npiggin@...il.com,
	peterz@...radead.org,
	dev.jain@....com,
	akpm@...ux-foundation.org,
	david@...hat.com,
	ioworker0@...il.com
Cc: linux-arch@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	linux-alpha@...r.kernel.org,
	linux-snps-arc@...ts.infradead.org,
	loongarch@...ts.linux.dev,
	linux-mips@...r.kernel.org,
	linux-parisc@...r.kernel.org,
	linux-um@...ts.infradead.org,
	Qi Zheng <zhengqi.arch@...edance.com>
Subject: [PATCH 0/7] enable PT_RECLAIM on all 64-bit architectures

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

Hi all,

This series aims to enable PT_RECLAIM on all 64-bit architectures.

On a 64-bit system, madvise(MADV_DONTNEED) may cause a large number of empty PTE
page table pages (such as 100GB+). To resolve this problem, we need to enable
PT_RECLAIM, which depends on MMU_GATHER_RCU_TABLE_FREE.

Therefore, this series first enables MMU_GATHER_RCU_TABLE_FREE on all 64-bit
architectures, and finally makes PT_RECLAIM depend on MMU_GATHER_RCU_TABLE_FREE
&& 64BIT. This way, PT_RECLAIM can be enabled by default on all 64-bit
architectures.

Comments and suggestions are welcome!

Thanks,
Qi

Qi Zheng (7):
  alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE
  arc: mm: enable MMU_GATHER_RCU_TABLE_FREE
  loongarch: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mips: mm: enable MMU_GATHER_RCU_TABLE_FREE
  parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
  um: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mm: make PT_RECLAIM depend on MMU_GATHER_RCU_TABLE_FREE && 64BIT

 arch/alpha/Kconfig                   | 1 +
 arch/alpha/include/asm/tlb.h         | 8 +++++---
 arch/arc/Kconfig                     | 1 +
 arch/arc/include/asm/pgalloc.h       | 9 ++++++---
 arch/loongarch/Kconfig               | 1 +
 arch/loongarch/include/asm/pgalloc.h | 6 ++++--
 arch/mips/Kconfig                    | 1 +
 arch/mips/include/asm/pgalloc.h      | 6 ++++--
 arch/parisc/Kconfig                  | 1 +
 arch/parisc/include/asm/tlb.h        | 6 ++++--
 arch/um/Kconfig                      | 1 +
 arch/x86/Kconfig                     | 1 -
 mm/Kconfig                           | 6 +-----
 13 files changed, 30 insertions(+), 18 deletions(-)

-- 
2.20.1