From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from foss.arm.com (foss.arm.com [217.140.110.172])
	by smtp.subspace.kernel.org (Postfix) with ESMTP id 6BC4A2DE6F5;
	Fri, 24 Oct 2025 12:17:03 +0000 (UTC)
Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172
ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;
	t=1761308224; cv=none; b=FGghBouecGo0IGY5kPBEFakOAtz6NC42cFyCuGnd/QBPauuTKDMd6ijFEx0OU1ctPXv9phOCcl3yZUwfOue6Iow9PY8cQBIgVyf+CyF/Dxm4Hm48GOQWQES4ReSbOdgPdndQ8FCy3NAJZt1C9zciP8N6OLn30zTgebBPekF5nPQ=
ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org;
	s=arc-20240116; t=1761308224; c=relaxed/simple;
	bh=cvFdvuPr794gDedSFsrccdsdKFYkvyjvhZA7QrQhBgQ=;
	h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From:
	 In-Reply-To:Content-Type; b=FTq6PbSE8dvi99mFDfRAKMqY7xnrScFs/qlwiOQkE9ZN/1qZrPyNSrDHJtO5cpa/5BV2dsqpgcicpYkdaV9xm29P4ZZLP0IgBWWtOp0YzjJFXJOh14AxcW9svJMyfcRQETC4Yw7NpyrcuOxMQd9ZgST6crrRM04wCsr5bzSRuKo=
ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172
Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com
Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com
Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14])
	by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 03DAB1D34;
	Fri, 24 Oct 2025 05:16:55 -0700 (PDT)
Received: from [10.44.160.74] (e126510-lin.lund.arm.com [10.44.160.74])
	by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 44C443F66E;
	Fri, 24 Oct 2025 05:16:55 -0700 (PDT)
Message-ID: <451403ce-f250-44ac-8e2f-b7b27ee9f588@arm.com>
Date: Fri, 24 Oct 2025 14:16:52 +0200
Precedence: bulk
X-Mailing-List: linux-kernel@vger.kernel.org
List-Id: <linux-kernel.vger.kernel.org>
List-Subscribe: <mailto:linux-kernel+subscribe@vger.kernel.org>
List-Unsubscribe: <mailto:linux-kernel+unsubscribe@vger.kernel.org>
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v3 09/13] powerpc/mm: replace batch->active with
 in_lazy_mmu_mode()
To: David Hildenbrand <david@redhat.com>, linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org, Alexander Gordeev <agordeev@linux.ibm.com>,
 Andreas Larsson <andreas@gaisler.com>,
 Andrew Morton <akpm@linux-foundation.org>,
 Boris Ostrovsky <boris.ostrovsky@oracle.com>, Borislav Petkov
 <bp@alien8.de>, Catalin Marinas <catalin.marinas@arm.com>,
 Christophe Leroy <christophe.leroy@csgroup.eu>,
 Dave Hansen <dave.hansen@linux.intel.com>,
 "David S. Miller" <davem@davemloft.net>, "H. Peter Anvin" <hpa@zytor.com>,
 Ingo Molnar <mingo@redhat.com>, Jann Horn <jannh@google.com>,
 Juergen Gross <jgross@suse.com>, "Liam R. Howlett"
 <Liam.Howlett@oracle.com>, Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
 Madhavan Srinivasan <maddy@linux.ibm.com>,
 Michael Ellerman <mpe@ellerman.id.au>, Michal Hocko <mhocko@suse.com>,
 Mike Rapoport <rppt@kernel.org>, Nicholas Piggin <npiggin@gmail.com>,
 Peter Zijlstra <peterz@infradead.org>, Ryan Roberts <ryan.roberts@arm.com>,
 Suren Baghdasaryan <surenb@google.com>, Thomas Gleixner
 <tglx@linutronix.de>, Vlastimil Babka <vbabka@suse.cz>,
 Will Deacon <will@kernel.org>, Yeoreum Yun <yeoreum.yun@arm.com>,
 linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org,
 sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org
References: <20251015082727.2395128-1-kevin.brodsky@arm.com>
 <20251015082727.2395128-10-kevin.brodsky@arm.com>
 <8d5243ec-3edd-49a6-ab51-16643a709d84@redhat.com>
Content-Language: en-GB
From: Kevin Brodsky <kevin.brodsky@arm.com>
In-Reply-To: <8d5243ec-3edd-49a6-ab51-16643a709d84@redhat.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit

On 23/10/2025 22:02, David Hildenbrand wrote:
> On 15.10.25 10:27, Kevin Brodsky wrote:
>> The generic lazy_mmu layer now tracks whether a task is in lazy MMU
>> mode. As a result we no longer need to track whether the per-CPU TLB
>> batch struct is active - we know it is if in_lazy_mmu_mode() returns
>> true.
>
> It's worth adding that disabling preemption while enabled makes sure
> that we cannot reschedule while in lazy MMU mode, so when the per-CPU
> TLB batch structure is active.

Yes good point, otherwise this change doesn't make sense. I'll add that.

- Kevin