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From: Wei Yang <weiyang.kernel@gmail.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: One comment on the __release_region in kernel/resource.c
Date: Mon, 3 Oct 2011 21:35:17 +0800	[thread overview]
Message-ID: <CADLM8XP09kFhxjMYbxD80+4cS00cm2aWZE1Zvjoby0Afrdz9eQ@mail.gmail.com> (raw)
In-Reply-To: <CAMuHMdVuMHjbDkAdrkfTS-ZaYCwN-avihsQyDsOAVFt+PdWqYw@mail.gmail.com>

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2011/10/3 Geert Uytterhoeven <geert@linux-m68k.org>

> On Mon, Oct 3, 2011 at 12:24, KAMEZAWA Hiroyuki
> <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> > On Sun, 2 Oct 2011 21:57:07 +0800
> > Wei Yang <weiyang.kernel@gmail.com> wrote:
> >
> >> Dear experts,
> >>
> >> I am viewing the source code of __release_region() in kernel/resource.c.
> >> And I have one comment for the performance issue.
> >>
> >> For example, we have a resource tree like this.
> >> 10-89
> >>    20-79
> >>        30-49
> >>        55-59
> >>        60-64
> >>        65-69
> >>    80-89
> >> 100-279
> >>
> >> If the caller wants to release a region of [50,59], the original code
> will
>                                               ^^^^^^^
> Do you really mean [50,59]?
>
Yes.

> I don't think that's allowed, as the tree has [55,59], so you would release
> a
> larger region that allocated.
>
So you mean the case I mentioned will not happen?
Actually, I believe every developer should pass the resource region which
has been allocated.
While if some one made a mistake and pass a region which is not allocated
before and overlap
some "BUSY" region?


>
> Gr{oetje,eeting}s,
>
>                         Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 --
> geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker.
> But
> when I'm talking to journalists I just say "programmer" or something like
> that.
>                                 -- Linus Torvalds
>



-- 
Wei Yang
Help You, Help Me

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  reply	other threads:[~2011-10-03 13:35 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-02 13:57 Wei Yang
2011-10-03 10:24 ` KAMEZAWA Hiroyuki
2011-10-03 11:15   ` Geert Uytterhoeven
2011-10-03 13:35     ` Wei Yang [this message]
2011-10-03 14:03       ` Geert Uytterhoeven
2011-10-03 14:24         ` Wei Yang
2011-10-04 14:17         ` Wei Yang
2011-10-03 13:30   ` Wei Yang

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