Re: [PATCH 3/3] mm/memory-failure: send SIGBUS in the event of thp split fail

Jane Chu
2024-05-08T16:56:30Z

On 5/8/2024 2:03 AM, Miaohe Lin wrote:

> On 2024/5/2 7:24, Jane Chu wrote:
>> When handle hwpoison in a GUP longterm pin'ed thp page,
>> try_to_split_thp_page() will fail. And at this point, there is little else
>> the kernel could do except sending a SIGBUS to the user process, thus
>> give it a chance to recover.
> It seems the user process will still receive SIGBUS via kill_accessing_process()
> when (re-)access thp later. So they should have a chance to recover already.
> Or am I miss something?

The concern is about real UE consumption in which case, it's desirable
to kill the process ASAP without having to relying on subsequent
access.  Also to honor processes' MCE-early-kill request.
kill_accessing_process() is very conservative in that, it doesn't check
other processes that have the poisoned page mapped.

thanks,

-jane

>
> Thanks.
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