From: Miaohe Lin <linmiaohe@huawei.com>
To: Matthew Wilcox <willy@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: <hughd@google.com>, <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm/mlock: remove unneeded start >= vma->vm_end check
Date: Thu, 31 Mar 2022 09:50:36 +0800 [thread overview]
Message-ID: <602a1658-9b29-1752-d5a0-c5dd338fcc4c@huawei.com> (raw)
In-Reply-To: <c0ff39e2-27fc-170f-00f5-d5e9ab5a22cd@huawei.com>
On 2022/3/15 20:30, Miaohe Lin wrote:
> On 2022/3/15 0:17, Matthew Wilcox wrote:
>> On Mon, Mar 14, 2022 at 11:32:23PM +0800, Miaohe Lin wrote:
>>> If find_vma returns a vma, it must satisfies that start < vma->vm_end.
>>> Since vma list is sorted in the ascending order, so we will never see
>>> start >= vma->vm_end here. Remove this unneeded check.
>>
>> faulty logic; vm_start + len might wrap.
>
> Many thanks for comment. I agree with you about "vm_start + len" might wrap.
> But what I mean here is that we will never see "start" >= vma->vm_end here
> as find_vma guarantees this. And I leave the "start + len <= vma->vm_start"
> check untouched. So my cleanup should be right. Or am I miss something?
>
friendly ping. :)
> Thanks.
>
>>
>> .
>>
>
next prev parent reply other threads:[~2022-03-31 1:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-14 15:32 [PATCH] mm/mlock: remove unneeded start >= vma->vm_end check Miaohe Lin
2022-03-14 16:17 ` Matthew Wilcox
2022-03-15 12:30 ` Miaohe Lin
2022-03-31 1:50 ` Miaohe Lin [this message]
2022-04-06 9:17 ` Miaohe Lin
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