Re: [PATCH] mm: remove remaining references to NUMA hinting bits and helpers -fix

[Steve Capper <steve.capper@linaro.org>]

On Fri, Jan 30, 2015 at 10:04:06AM +0000, Mel Gorman wrote:
> The patch "mm: remove remaining references to NUMA hinting bits and helpers"
> was meant to remove NUMA hinting bits and helpers but broke is_swap_pte.
> From the original bug report
> 
> 	For at least the past couple of days tests of libhugetlbfs have
> 	been hanging on mustang in the mlock test running ARMv8 defconfig
> 	with both 32 bit and 64 bit userspace - after the mprotect test
> 	(the one before it) we get no console output for several hours so
> 	it appears that the test has deadlocked.  The tail of the log is:
> 
> 	| find_path (2M: 64):   PASS
> 	| unlinked_fd (2M: 64): PASS
> 	| readback (2M: 64):    PASS
> 	| truncate (2M: 64):    PASS
> 	| shared (2M: 64):      PASS
> 	| mprotect (2M: 64):    PASS
> 
> This patch should address the problem and is a fix to the mmotm patch
> mm-remove-remaining-references-to-numa-hinting-bits-and-helpers.patch
> 
> Reported-by: Mark Brown <broonie@kernel.org>
> Signed-off-by: Mel Gorman <mgorman@suse.de>

Acked-by: Steve Capper <steve.capper@linaro.org>

> ---
>  include/linux/swapops.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/swapops.h b/include/linux/swapops.h
> index 73ca28070a92..cedf3d3c373f 100644
> --- a/include/linux/swapops.h
> +++ b/include/linux/swapops.h
> @@ -54,7 +54,7 @@ static inline pgoff_t swp_offset(swp_entry_t entry)
>  /* check whether a pte points to a swap entry */
>  static inline int is_swap_pte(pte_t pte)
>  {
> -	return !pte_none(pte);
> +	return !pte_none(pte) && !pte_present(pte);
>  }
>  #endif
>