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Message-ID: <4FA02603.80807@openvz.org>
Date: Tue, 01 May 2012 22:05:55 +0400
From: Konstantin Khlebnikov <khlebnikov@openvz.org>
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To: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
CC: "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andi Kleen <andi@firstfloor.org>
Subject: Re: [PATCH RFC 3/3] proc/smaps: show amount of hwpoison pages
References: <20120430112903.14137.81692.stgit@zurg> <20120430112910.14137.28935.stgit@zurg> <CAHGf_=rWDMMv2dKz3paV2MnjsCNWBa2BaUTi+RnDo8DZ4zEr=g@mail.gmail.com>
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KOSAKI Motohiro wrote:
> On Mon, Apr 30, 2012 at 7:29 AM, Konstantin Khlebnikov
> <khlebnikov@openvz.org>  wrote:
>> This patch adds line "HWPoinson:<size>  kB" into /proc/pid/smaps if
>> CONFIG_MEMORY_FAILURE=y and some HWPoison pages were found.
>> This may be useful for searching applications which use a broken memory.
>
> I dislike "maybe useful" claim. If we don't know exact motivation of a feature,
> we can't maintain them especially when a bugfix can't avoid ABI change.
>
> Please write down exact use case.

I don't know how to exactly use this hw-poison stuff, but smaps suppose to
export state of ptes in vma. It seems to rational to show also hw-poisoned ptes,
since kernel has this feature and pte can be in hw-poisoned state.

and now everyone can easily find them:
# sudo grep HWPoison /proc/*/smaps
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