Subject: Re: [RFC 01/11] mm: use SWAP_SUCCESS instead of 0
To: Minchan Kim <minchan@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
References: <1488436765-32350-1-git-send-email-minchan@kernel.org>
 <1488436765-32350-2-git-send-email-minchan@kernel.org>
Cc: kernel-team@lge.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@suse.com>,
        "Kirill A . Shutemov" <kirill@shutemov.name>
From: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Date: Thu, 2 Mar 2017 19:57:10 +0530
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On 03/02/2017 12:09 PM, Minchan Kim wrote:
> SWAP_SUCCESS defined value 0 can be changed always so don't rely on
> it. Instead, use explict macro.

Right. But should not we move the changes to the callers last in the
patch series after doing the cleanup to the try_to_unmap() function
as intended first.

> > Cc: Kirill A. Shutemov <kirill@shutemov.name>
> Signed-off-by: Minchan Kim <minchan@kernel.org>
> ---
>  mm/huge_memory.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 092cc5c..fe2ccd4 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2114,7 +2114,7 @@ static void freeze_page(struct page *page)
>  		ttu_flags |= TTU_MIGRATION;
>  
>  	ret = try_to_unmap(page, ttu_flags);
> -	VM_BUG_ON_PAGE(ret, page);
> +	VM_BUG_ON_PAGE(ret != SWAP_SUCCESS, page);
>  }
>  
>  static void unfreeze_page(struct page *page)
>