linux-kernel - Re: [PATCH v4 7/8] mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE

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Message-ID: <1663ae90-3247-4e12-a25a-049fc3281e19@linux.dev>
Date: Fri, 6 Feb 2026 19:13:59 +0800
From: Qi Zheng <qi.zheng@...ux.dev>
To: "David Hildenbrand (Arm)" <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: Re: [PATCH v4 7/8] mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to
 CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config



On 2/6/26 7:06 PM, David Hildenbrand (Arm) wrote:
> On 1/27/26 13:13, Qi Zheng wrote:
>> From: Qi Zheng <zhengqi.arch@...edance.com>
>>
>> For architectures that define __HAVE_ARCH_TLB_REMOVE_TABLE, the page
>> tables at the pmd/pud level are generally not of struct ptdesc type, and
>> do not have pt_rcu_head member, thus these architectures cannot support
>> PT_RECLAIM.
>>
>> In preparation for enabling PT_RECLAIM on more architectures, convert
>> __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config,
>> so that we can make conditional judgments in Kconfig.
>>
>> Signed-off-by: Qi Zheng <zhengqi.arch@...edance.com>
>> ---
>>   arch/powerpc/Kconfig            | 1 +
>>   arch/powerpc/include/asm/tlb.h  | 1 -
>>   arch/sparc/Kconfig              | 1 +
>>   arch/sparc/include/asm/tlb_64.h | 1 -
>>   include/asm-generic/tlb.h       | 2 +-
>>   mm/Kconfig                      | 3 +++
>>   6 files changed, 6 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index 9537a61ebae02..b47aa8fd62742 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -304,6 +304,7 @@ config PPC
>>       select LOCK_MM_AND_FIND_VMA
>>       select MMU_GATHER_PAGE_SIZE
>>       select MMU_GATHER_RCU_TABLE_FREE
>> +    select HAVE_ARCH_TLB_REMOVE_TABLE
>>       select MMU_GATHER_MERGE_VMAS
>>       select MMU_LAZY_TLB_SHOOTDOWN        if PPC_BOOK3S_64
>>       select MODULES_USE_ELF_RELA
>> diff --git a/arch/powerpc/include/asm/tlb.h b/arch/powerpc/include/ 
>> asm/tlb.h
>> index 2058e8d3e0138..1ca7d4c4b90db 100644
>> --- a/arch/powerpc/include/asm/tlb.h
>> +++ b/arch/powerpc/include/asm/tlb.h
>> @@ -37,7 +37,6 @@ extern void tlb_flush(struct mmu_gather *tlb);
>>    */
>>   #define tlb_needs_table_invalidate()    radix_enabled()
>> -#define __HAVE_ARCH_TLB_REMOVE_TABLE
>>   /* Get the generic bits... */
>>   #include <asm-generic/tlb.h>
>> diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
>> index a630d373e6453..25fa2908d6152 100644
>> --- a/arch/sparc/Kconfig
>> +++ b/arch/sparc/Kconfig
>> @@ -74,6 +74,7 @@ config SPARC64
>>       select HAVE_KRETPROBES
>>       select HAVE_KPROBES
>>       select MMU_GATHER_RCU_TABLE_FREE if SMP
>> +    select HAVE_ARCH_TLB_REMOVE_TABLE if SMP
> 
> Why the SMP? At least in tlb_64.h, it was not protected by SMP IIUC.

Ah, It's just simply aligned with the MMU_GATHER_RCU_TABLE_FREE above.

> 
> Apart from that LGTM.

Thanks!

>