From: Miaohe Lin <linmiaohe@huawei.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: <akpm@linux-foundation.org>, <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: Tue, 15 Mar 2022 20:30:49 +0800 [thread overview]
Message-ID: <c0ff39e2-27fc-170f-00f5-d5e9ab5a22cd@huawei.com> (raw)
In-Reply-To: <Yi9qq9hVloDXcW4b@casper.infradead.org>
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?
Thanks.
>
> .
>
next prev parent reply other threads:[~2022-03-15 12:30 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-14 15:32 Miaohe Lin
2022-03-14 16:17 ` Matthew Wilcox
2022-03-15 12:30 ` Miaohe Lin [this message]
2022-03-31 1:50 ` Miaohe Lin
2022-04-06 9:17 ` Miaohe Lin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=c0ff39e2-27fc-170f-00f5-d5e9ab5a22cd@huawei.com \
--to=linmiaohe@huawei.com \
--cc=akpm@linux-foundation.org \
--cc=hughd@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox