linux-kernel - Re: mce: a question about memory_failure_early_kill in memory

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Message-ID: <20160420070735.GA10125@hori1.linux.bs1.fc.nec.co.jp>
Date:	Wed, 20 Apr 2016 07:07:35 +0000
From:	Naoya Horiguchi <n-horiguchi@...jp.nec.com>
To:	Xishi Qiu <qiuxishi@...wei.com>
CC:	Linux MM <linux-mm@...ck.org>, LKML <linux-kernel@...r.kernel.org>
Subject: Re: mce: a question about memory_failure_early_kill in
 memory_failure()

On Tue, Apr 19, 2016 at 07:13:34PM +0800, Xishi Qiu wrote:
> /proc/sys/vm/memory_failure_early_kill
> 
> 1: means kill all processes that have the corrupted and not reloadable page mapped.
> 0: means only unmap the corrupted page from all processes and only kill a process
> who tries to access it.
> 
> If set memory_failure_early_kill to 0, and memory_failure() has been called.
> memory_failure()
> 	hwpoison_user_mappings()
> 		collect_procs()  // the task(with no PF_MCE_PROCESS flag) is not in the tokill list
> 			try_to_unmap()
> 
> If the task access the memory, there will be a page fault,
> so the task can not access the original page again, right?

Yes, right. That's the behavior in default "late kill" case.

I'm guessing that you might have a more specific problem around this code.
If so, please feel free to ask with detail.

Thanks,
Naoya Horiguchi