Re: [PATCH 1/3] mm/migrate: clean up useless code in migrate_vma_collect_pmd()

[Pingfan Liu <kernelfans@gmail.com>]

On Tue, Aug 06, 2019 at 06:35:03AM -0700, Matthew Wilcox wrote:
> 
> This needs something beyond the subject line.  Maybe ...
> 
> After these assignments, we either restart the loop with a fresh variable,
> or we assign to the variable again without using the value we've assigned.
> 
> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> 
> >  			goto next;
> >  		}
> > -		pfn = page_to_pfn(page);
> 
> After you've done all this, as far as I can tell, the 'pfn' variable is
> only used in one arm of the conditions, so it can be moved there.
> 
> ie something like:
> 
> -               unsigned long mpfn, pfn;
> +               unsigned long mpfn;
> ...
> -               pfn = pte_pfn(pte);
> ...
> +                       unsigned long pfn = pte_pfn(pte);
> +
> 
This makes code better. Thank you for the suggestion. Will send v2 for
this patch.

Regards,
	Pingfan