From: Chen Gang <gchen_5i5j@21cn.com>
To: gang.chen.5i5j@gmail.com, akpm@linux-foundation.org, mhocko@suse.cz
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/mmap.c: Remove useless statement "vma = NULL" in find_vma()
Date: Thu, 03 Sep 2015 12:02:28 +0800 [thread overview]
Message-ID: <55E7C654.2080309@21cn.com> (raw)
In-Reply-To: <1441252346-2323-1-git-send-email-gang.chen.5i5j@gmail.com>
Hello all:
I also want to consult: the comments of find_vma() says:
"Look up the first VMA which satisfies addr < vm_end, ..."
Is it OK? (why not "vm_start <= addr < vm_end"), need we let "vma = tmp"
in "if (tmp->vm_start <= addr)"? -- it looks the comments is not match
the implementation, precisely (maybe not 1st VMA).
Thanks.
On 9/3/15 11:52, gang.chen.5i5j@gmail.com wrote:
> From: Chen Gang <gang.chen.5i5j@gmail.com>
>
> Before the main looping, vma is already is NULL, so need not set it to
> NULL, again.
>
> Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
> ---
> mm/mmap.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index df6d5f0..4db7cf0 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -2054,7 +2054,6 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
> return vma;
>
> rb_node = mm->mm_rb.rb_node;
> - vma = NULL;
>
> while (rb_node) {
> struct vm_area_struct *tmp;
>
--
Chen Gang (陈刚)
Open, share, and attitude like air, water, and life which God blessed
next prev parent reply other threads:[~2015-09-03 4:02 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-03 3:52 gang.chen.5i5j
2015-09-03 4:02 ` Chen Gang [this message]
2015-09-05 14:03 Chen Gang
2015-09-07 12:36 ` Oleg Nesterov
[not found] ` <55EEED66.6090509@hotmail.com>
2015-09-08 14:14 ` Chen Gang
2015-09-09 16:26 ` Oleg Nesterov
[not found] ` <55F0B6C2.2000706@hotmail.com>
2015-09-09 22:44 ` Chen Gang
2015-09-10 18:19 ` Oleg Nesterov
2015-09-10 22:20 ` Chen Gang
2015-09-08 23:14 ` David Rientjes
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