Re: [PATCH v2 3/3] mm/hwpoison: fix return value of madvise_hwpoison

From: Chen Gong
Date: Tue Aug 27 2013 - 03:49:24 EST


On Mon, Aug 26, 2013 at 11:41:36PM -0400, Naoya Horiguchi wrote:
> Date: Mon, 26 Aug 2013 23:41:36 -0400
> From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> To: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>, Andi Kleen
> <andi@xxxxxxxxxxxxxx>, Fengguang Wu <fengguang.wu@xxxxxxxxx>, Tony Luck
> <tony.luck@xxxxxxxxx>, gong.chen@xxxxxxxxxxxxxxx, linux-mm@xxxxxxxxx,
> linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2 3/3] mm/hwpoison: fix return value of
> madvise_hwpoison
> User-Agent: Mutt 1.5.21 (2010-09-15)
>
> On Tue, Aug 27, 2013 at 11:38:27AM +0800, Wanpeng Li wrote:
> > Hi Naoya,
> > On Mon, Aug 26, 2013 at 11:28:16PM -0400, Naoya Horiguchi wrote:
> > >On Tue, Aug 27, 2013 at 10:39:31AM +0800, Wanpeng Li wrote:
> > >> The return value outside for loop is always zero which means madvise_hwpoison
> > >> return success, however, this is not truth for soft_offline_page w/ failure
> > >> return value.
> > >
> > >I don't understand what you want to do for what reason. Could you clarify
> > >those?
> >
> > int ret is defined in two place in madvise_hwpoison. One is out of for
> > loop and its value is always zero(zero means success for madvise), the
> > other one is in for loop. The soft_offline_page function maybe return
> > -EBUSY and break, however, the ret out of for loop is return which means
> > madvise_hwpoison success.
>
> Oh, I see. Thanks.
>
I don't think such change is a good idea. The original code is obviously
easy to confuse people. Why not removing redundant local variable?

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