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 A5D49C433EF
	for <linux-kernel@archiver.kernel.org>; Tue, 19 Apr 2022 11:26:52 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1351274AbiDSL3c (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Tue, 19 Apr 2022 07:29:32 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33912 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S239095AbiDSL32 (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 19 Apr 2022 07:29:28 -0400
Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61F1624F33
        for <linux-kernel@vger.kernel.org>; Tue, 19 Apr 2022 04:26:46 -0700 (PDT)
Received: from canpemm500002.china.huawei.com (unknown [172.30.72.55])
        by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4KjLzf42k0zFqRx;
        Tue, 19 Apr 2022 19:24:14 +0800 (CST)
Received: from [10.174.177.76] (10.174.177.76) by
 canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server
 (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id
 15.1.2375.24; Tue, 19 Apr 2022 19:26:43 +0800
Subject: Re: [PATCH v2] mm/swapfile: unuse_pte can map random data if swap
 read fails
To:     Alistair Popple <apopple@nvidia.com>
CC:     <akpm@linux-foundation.org>, <willy@infradead.org>,
        <vbabka@suse.cz>, <dhowells@redhat.com>, <neilb@suse.de>,
        <david@redhat.com>, <surenb@google.com>, <minchan@kernel.org>,
        <peterx@redhat.com>, <sfr@canb.auug.org.au>,
        <rcampbell@nvidia.com>, <naoya.horiguchi@nec.com>,
        <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>
References: <20220416030549.60559-1-linmiaohe@huawei.com>
 <87tuapk9n7.fsf@nvdebian.thelocal> <87r15tjy76.fsf@nvdebian.thelocal>
From:   Miaohe Lin <linmiaohe@huawei.com>
Message-ID: <e320fb01-7d53-668e-53b5-463312ae0909@huawei.com>
Date:   Tue, 19 Apr 2022 19:26:43 +0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.6.0
MIME-Version: 1.0
In-Reply-To: <87r15tjy76.fsf@nvdebian.thelocal>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-Originating-IP: [10.174.177.76]
X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To
 canpemm500002.china.huawei.com (7.192.104.244)
X-CFilter-Loop: Reflected
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 2022/4/19 15:53, Alistair Popple wrote:
> Also in madvise_free_pte_range() you could just remove the swap entry as it's no
> longer needed.
> 

This swap entry will be removed in madvise_dontneed_single_vma().
And in madvise_free_pte_range(), we may need to keep it as same as
hwpoison entry. Or am I supposed to remove it even if hwpoison entry
is reused later?

Thanks!

> Alistair Popple <apopple@nvidia.com> writes:
> 
>> Miaohe Lin <linmiaohe@huawei.com> writes:
>>
...