From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
	by smtp.lore.kernel.org (Postfix) with ESMTP id BD8A4C433FE
	for <linux-kernel@archiver.kernel.org>; Mon, 21 Mar 2022 18:27:50 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1352154AbiCUS3O (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Mon, 21 Mar 2022 14:29:14 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55192 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S237961AbiCUS3L (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 21 Mar 2022 14:29:11 -0400
Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 791D86B0B7;
        Mon, 21 Mar 2022 11:27:45 -0700 (PDT)
Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140])
        (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
        (No client certificate requested)
        by dfw.source.kernel.org (Postfix) with ESMTPS id 12AF761136;
        Mon, 21 Mar 2022 18:27:45 +0000 (UTC)
Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0287DC340E8;
        Mon, 21 Mar 2022 18:27:36 +0000 (UTC)
Date:   Mon, 21 Mar 2022 18:27:33 +0000
From:   Catalin Marinas <catalin.marinas@arm.com>
To:     Will Deacon <will@kernel.org>
Cc:     David Hildenbrand <david@redhat.com>, linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Hugh Dickins <hughd@google.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        David Rientjes <rientjes@google.com>,
        Shakeel Butt <shakeelb@google.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Mike Rapoport <rppt@linux.ibm.com>,
        Yang Shi <shy828301@gmail.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Matthew Wilcox <willy@infradead.org>,
        Vlastimil Babka <vbabka@suse.cz>, Jann Horn <jannh@google.com>,
        Michal Hocko <mhocko@kernel.org>,
        Nadav Amit <namit@vmware.com>, Rik van Riel <riel@surriel.com>,
        Roman Gushchin <guro@fb.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Peter Xu <peterx@redhat.com>,
        Donald Dutile <ddutile@redhat.com>,
        Christoph Hellwig <hch@lst.de>,
        Oleg Nesterov <oleg@redhat.com>, Jan Kara <jack@suse.cz>,
        Liang Zhang <zhangliang5@huawei.com>,
        Pedro Gomes <pedrodemargomes@gmail.com>,
        Oded Gabbay <oded.gabbay@gmail.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, linux-mm@kvack.org,
        x86@kernel.org, linux-arm-kernel@lists.infradead.org,
        linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org
Subject: Re: [PATCH v1 4/7] arm64/pgtable: support
 __HAVE_ARCH_PTE_SWP_EXCLUSIVE
Message-ID: <YjjDlajNUdHgOOWM@arm.com>
References: <20220315141837.137118-1-david@redhat.com>
 <20220315141837.137118-5-david@redhat.com>
 <YjIr9f9qaz4xITVd@arm.com>
 <20220321143802.GC11145@willie-the-truck>
 <ea570f92-f896-7f9b-91c4-ad0a025bb340@redhat.com>
 <20220321174404.GA11389@willie-the-truck>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220321174404.GA11389@willie-the-truck>
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, Mar 21, 2022 at 05:44:05PM +0000, Will Deacon wrote:
> On Mon, Mar 21, 2022 at 04:07:48PM +0100, David Hildenbrand wrote:
> > So the example you gave cannot possibly have that bit set. From what I
> > understand, it should be fine. But I have no real preference: I can also
> > just stick to the original patch, whatever you prefer.
> 
> I think I'd prefer to stay on the safe side and stick with bit 2 as you
> originally proposed. If we need to support crazy numbers of swapfiles
> in future then we can revisit the idea of allocating bit 1.

Sounds fine to me. David, feel free to keep my reviewed-by on the
original patch.

-- 
Catalin