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Subject: Re: [PATCH v4 1/2] mm/memory-failure: introduce "hwpoisoned-pages"
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To:     David Hildenbrand <david@redhat.com>,
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        <naoya.horiguchi@nec.com>
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        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        zhenwei pi <pizhenwei@bytedance.com>
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 <20220614070934.GA1627546@hori.linux.bs1.fc.nec.co.jp>
 <66c43dac-32ac-5801-c76c-01607d68e38b@redhat.com>
From:   Miaohe Lin <linmiaohe@huawei.com>
Message-ID: <c436f65d-d219-d2a5-0275-462b3a10879e@huawei.com>
Date:   Tue, 14 Jun 2022 16:19:26 +0800
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On 2022/6/14 15:13, David Hildenbrand wrote:
> 	   &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.

This approach should be more straightforward. ;)

>