From: Miaohe Lin <linmiaohe@huawei.com>
To: David Hildenbrand <david@redhat.com>,
Alistair Popple <apopple@nvidia.com>
Cc: <akpm@linux-foundation.org>, <willy@infradead.org>,
<vbabka@suse.cz>, <dhowells@redhat.com>, <neilb@suse.de>,
<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>
Subject: Re: [PATCH v2] mm/swapfile: unuse_pte can map random data if swap read fails
Date: Wed, 20 Apr 2022 16:37:04 +0800 [thread overview]
Message-ID: <4d14dcfc-0053-bfd6-433e-f264d22069d0@huawei.com> (raw)
In-Reply-To: <e2352989-959d-2969-40e4-2d92eb8a5f9b@redhat.com>
On 2022/4/20 15:07, David Hildenbrand wrote:
> On 20.04.22 08:15, Miaohe Lin wrote:
>> On 2022/4/20 8:25, Alistair Popple wrote:
>>> Miaohe Lin <linmiaohe@huawei.com> writes:
>>>
>>>> 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?
>>>
>>> Why would we need to keep it for MADV_FREE though? It only works on private
>>> anonymous memory, and once the MADV_FREE operation has succeeded callers can
>>> expect they might get zero-fill pages if accessing the memory again. Therefore
>>> it should be safe to delete the entry. I think that applies equally to a
>>> hwpoison entry too - there's no reason to kill the process if it has called
>>> MADV_FREE on the range.
>>
>> I tend to agree. We can drop the swapin error entry and hwpoison entry when MADV_FREE
>> is called. Should I squash these into the current patch or a separate one is preferred?
>>
>
> That should go into a separate patch.
Will do. Many thanks for your suggestion.
>
next prev parent reply other threads:[~2022-04-20 8:37 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-16 3:05 [PATCH v2] mm/swapfile: unuse_pte can map random data if swap read fails Miaohe Lin
2022-04-19 3:51 ` Alistair Popple
2022-04-19 7:29 ` Miaohe Lin
2022-04-19 7:39 ` David Hildenbrand
2022-04-19 8:08 ` Alistair Popple
2022-04-19 11:14 ` David Hildenbrand
2022-04-19 16:16 ` Peter Xu
2022-04-19 11:14 ` Miaohe Lin
2022-04-19 7:53 ` Alistair Popple
2022-04-19 11:26 ` Miaohe Lin
2022-04-20 0:25 ` Alistair Popple
2022-04-20 6:15 ` Miaohe Lin
2022-04-20 7:07 ` David Hildenbrand
2022-04-20 8:37 ` Miaohe Lin [this message]
2022-04-19 7:37 ` David Hildenbrand
2022-04-19 11:21 ` Miaohe Lin
2022-04-19 11:46 ` David Hildenbrand
2022-04-19 12:00 ` Miaohe Lin
2022-04-19 12:12 ` David Hildenbrand
2022-04-19 12:45 ` Miaohe Lin
2022-04-19 21:36 ` Peter Xu
2022-04-20 5:56 ` [PATCH] mm/swap: Fix lost swap bits in unuse_pte() kernel test robot
2022-04-20 6:23 ` Miaohe Lin
2022-04-20 6:39 ` [kbuild-all] " Philip Li
2022-04-20 6:52 ` Miaohe Lin
2022-04-20 6:48 ` Chen, Rong A
2022-04-20 6:56 ` Miaohe Lin
2022-04-20 6:21 ` [PATCH v2] mm/swapfile: unuse_pte can map random data if swap read fails Miaohe Lin
2022-04-20 13:32 ` Peter Xu
2022-04-21 1:50 ` Miaohe Lin
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