+ parisc-mm-enable-mmu_gather_rcu_table_free.patch added to mm-new branch

+ parisc-mm-enable-mmu_gather_rcu_table_free.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
has been added to the -mm mm-new branch.  Its filename is
     parisc-mm-enable-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/parisc-mm-enable-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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days

------------------------------------------------------
From: Qi Zheng <zhengqi.arch@bytedance.com>
Subject: parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
Date: Wed, 17 Dec 2025 17:45:46 +0800

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,
first enable MMU_GATHER_RCU_TABLE_FREE to prepare for enabling the
PT_RECLAIM feature, which resolves this problem.

Link: https://lkml.kernel.org/r/e0445acf2c267f060e888a090cdd94cbf7f52dd3.1765963770.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
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: Huacai Chen <chenhuacai@kernel.org>
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/parisc/Kconfig           |    1 +
 arch/parisc/include/asm/tlb.h |    4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

--- a/arch/parisc/include/asm/tlb.h~parisc-mm-enable-mmu_gather_rcu_table_free
+++ a/arch/parisc/include/asm/tlb.h
@@ -5,8 +5,8 @@
 #include <asm-generic/tlb.h>
 
 #if CONFIG_PGTABLE_LEVELS == 3
-#define __pmd_free_tlb(tlb, pmd, addr)	pmd_free((tlb)->mm, pmd)
+#define __pmd_free_tlb(tlb, pmd, addr)	tlb_remove_ptdesc((tlb), virt_to_ptdesc(pmd))
 #endif
-#define __pte_free_tlb(tlb, pte, addr)	pte_free((tlb)->mm, pte)
+#define __pte_free_tlb(tlb, pte, addr)	tlb_remove_ptdesc((tlb), page_ptdesc(pte))
 
 #endif
--- a/arch/parisc/Kconfig~parisc-mm-enable-mmu_gather_rcu_table_free
+++ a/arch/parisc/Kconfig
@@ -79,6 +79,7 @@ config PARISC
 	select GENERIC_CLOCKEVENTS
 	select CPU_NO_EFFICIENT_FFS
 	select THREAD_INFO_IN_TASK
+	select MMU_GATHER_RCU_TABLE_FREE
 	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
 	select HAVE_ARCH_KGDB
_

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