RE: [PATCH] mm,hwpoison: return -EBUSY when page already poisoned

Luck, Tony
2021-03-08T18:54:42Z

>> So it should be safe to grab and hold a mutex. See patch below.
>
> The mutex approach looks simpler and safer, so I'm fine with it.

Thanks. Is that an "Acked-by:"?

>> /**
>> * memory_failure - Handle memory failure of a page.
>> * @pfn: Page Number of the corrupted page
>> @@ -1424,12 +1426,18 @@ int memory_failure(unsigned long pfn, int flags)
>> return -ENXIO;
>> }
>>
>> + mutex_lock(&mf_mutex);
>
> Is it better to take mutex before memory_failure_dev_pagemap() block?
> Or we don't have to protect against race for device memory?

No races (recovery is only attempted for errors in normal memory).

-Tony