From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38ECE2F2608; Wed, 19 Nov 2025 11:38:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763552335; cv=none; b=c737d3ExWQYYJmkZMmZK1Vp5rT3LogPrdKwgO10QvqO/5Qcqu3SeiiuTGnX/LiUw69ZcuT277dZVoq9pwDYDO9qT4tOpMTLJ4WF7WI+bpNnZR9GZo3zsL/zBHcT/oxMV8tT4EVlTuqdJoNSf2IcwhWBPPsZOTrb8SIuNPS65oO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763552335; c=relaxed/simple; bh=09EAP2XN+lRanTOPE2mYQg/imEyLIAMTytu/FERJ3KE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=cLxI9GR6+/CzO9jBOWHgT8N/3UNiIb3oa/eJgkBPSApgXkslT4O9lEUKpLvfLADoHRU+XIqYbAdjl1qIzFHLh+ICAlNce3T11g5xqc0wQpJcF5sAm6WJR4p9oUav8O+xeHC5B55ytta9xS2M3Mx5ISPlZLz+6FzvpBR7x+HOQso= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZbpzBxMP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZbpzBxMP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 510B7C2BCB4; Wed, 19 Nov 2025 11:38:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763552334; bh=09EAP2XN+lRanTOPE2mYQg/imEyLIAMTytu/FERJ3KE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ZbpzBxMPlijcUIWVvcKZTNGa7zCAJwZY9chXx+w8GbRHAR+rI1lSfYrqXSSvSDYaE MePEVV4EjqdFYyQgiSidQHYaWwO7pQarT3TKZOtNh3sSfSwIQ6SflX1gDL9lMSxLny w06MV9gY5w5TZlc4+ewlulKiXr9osdtN3qFwbuQWIMM4miVH0RvJzhNpO1lxypNit0 eeE/heuKvBJlnAAv4sK4Mv4MYw7Xohrvhu7Amo4HOBaY8PCND2DXnAiONttsXskaMh 8/Bno4vIYUEF05KYxb1WyXsUI4O64niqkk/pUg+0oPMnWbdq0tM2VTdA0KoQ6gV8im c4sJ+iwsxJ/XQ== Message-ID: <9b55623a-4606-4610-a0fe-55b8cd6b95e7@kernel.org> Date: Wed, 19 Nov 2025 12:38:46 +0100 Precedence: bulk X-Mailing-List: linux-parisc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 7/7] mm: enable PT_RECLAIM on all 64-bit architectures To: Qi Zheng , will@kernel.org, aneesh.kumar@kernel.org, npiggin@gmail.com, peterz@infradead.org, dev.jain@arm.com, akpm@linux-foundation.org, ioworker0@gmail.com, linmag7@gmail.com Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-alpha@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-um@lists.infradead.org, Qi Zheng References: From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 19.11.25 08:31, Qi Zheng wrote: > From: Qi Zheng > > Now, the MMU_GATHER_RCU_TABLE_FREE is enabled on all 64-bit architectures, > so make PT_RECLAIM depend on 64BIT, thereby enabling PT_RECLAIM on all > 64-bit architectures. > > Signed-off-by: Qi Zheng > --- > 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 eac2e86056902..96bff81fd4787 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -330,7 +330,6 @@ 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 d548976d0e0ad..94eec5c0cad96 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -1448,14 +1448,9 @@ 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 64BIT As discussed in the other thread, likely config PT_RECLAIM def_bool y depends on MMU_GATHER_RCU_TABLE_FREE && 64BIT Could be nice, and if possible even dropping the 64BIT limitation as well if there is no need to. -- Cheers David