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

[HORIGUCHI NAOYA(堀口 直也)]

On Mon, Mar 08, 2021 at 06:54:02PM +0000, Luck, Tony wrote:
> >> 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:"?

Not yet, I intended to add it after full patch is submitted
(with your Signed-off-by and commit log).

> 
> >>  /**
> >>   * 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).

OK, thanks.

- Naoya