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Date:   Tue, 14 Jun 2022 09:13:16 +0200
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Subject: Re: [PATCH v4 1/2] mm/memory-failure: introduce "hwpoisoned-pages"
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To:     =?UTF-8?B?SE9SSUdVQ0hJIE5BT1lBKOWggOWPoyDnm7TkuZ8p?= 
        <naoya.horiguchi@nec.com>, zhenwei pi <pizhenwei@bytedance.com>
Cc:     "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linmiaohe@huawei.com" <linmiaohe@huawei.com>
References: <20220614043830.99607-1-pizhenwei@bytedance.com>
 <20220614043830.99607-2-pizhenwei@bytedance.com>
 <20220614070934.GA1627546@hori.linux.bs1.fc.nec.co.jp>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
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	   &hwpoisoned_pages);
> 
> I'm not sure how useful this interface from userspace (controlling test process
> with this?).  Do we really need to expose this to userspace? 
> 
> 
> TBH I feel that another approach like below is more desirable:
> 
>   - define a new flag in "enum mf_flags" (for example named MF_SW_SIMULATED),
>   - set the flag when calling memory_failure() from the three callers
>     mentioned above,
>   - define a global variable (typed bool) in mm/memory_failure.c_to show that
>     the system has experienced a real hardware memory error events.
>   - once memory_failure() is called without MF_SW_SIMULATED, the new global
>     bool variable is set, and afterward unpoison_memory always fails with
>     -EOPNOTSUPP.

Exactly what I had in mind.

-- 
Thanks,

David / dhildenb