Re: [PATCH 06/24] HWPOISON: abort on failed unmap

[Andi Kleen]

On Wed, Dec 02, 2009 at 09:28:19PM +0800, Wu Fengguang wrote:
> On Wed, Dec 02, 2009 at 09:11:50PM +0800, Andi Kleen wrote:
> > >  	 * Now take care of user space mappings.
> > > +	 * Abort on fail: __remove_from_page_cache() assumes unmapped page.
> > >  	 */
> > > -	hwpoison_user_mappings(p, pfn, trapno);
> > > +	if (hwpoison_user_mappings(p, pfn, trapno) != SWAP_SUCCESS) {
> > > +		res = -EBUSY;
> > > +		goto out;
> > 
> > It would be good to print something in this case.
> 
> OK.

I'll add it.

> 
> > Did you actually see it during testing?
> 
> Perhaps not.
> 
> > Or maybe loop forever in the unmapper.
> 
> !SWAP_SUCCESS should be rare, so not necessary to loop forever?

I think the loop I originally added was overcautious and could
be even removed possibly now. It probably needs some more analysis how l
ikely unmapping failures really are.

-Andi

-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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