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Date:   Mon, 25 May 2020 09:55:40 -0400
From:   Qian Cai <cai@lca.pw>
To:     Yang Shi <yang.shi@linux.alibaba.com>
Cc:     kirill.shutemov@linux.intel.com, akpm@linux-foundation.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC linux-next PATCH] mm: khugepaged: remove error message when
 checking external pins
Message-ID: <20200525135540.GA18914@ovpn-112-169.phx2.redhat.com>
References: <1589317383-9595-1-git-send-email-yang.shi@linux.alibaba.com>
 <20200521145644.GA6367@ovpn-112-192.phx2.redhat.com>
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On Thu, May 21, 2020 at 10:56:51AM -0400, Qian Cai wrote:
> On Wed, May 13, 2020 at 05:03:03AM +0800, Yang Shi wrote:
> []
> >  mm/khugepaged.c | 24 +++++++++++++++++-------
> >  1 file changed, 17 insertions(+), 7 deletions(-)
> > 
> > diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> > index 1fdd677..048f5d4 100644
> > --- a/mm/khugepaged.c
> > +++ b/mm/khugepaged.c
> > @@ -602,12 +602,6 @@ static bool is_refcount_suitable(struct page *page)
> >  	if (PageSwapCache(page))
> >  		expected_refcount += compound_nr(page);
> >  
> > -	if (IS_ENABLED(CONFIG_DEBUG_VM) && expected_refcount > refcount) {
> > -		pr_err("expected_refcount (%d) > refcount (%d)\n",
> > -				expected_refcount, refcount);
> > -		dump_page(page, "Unexpected refcount");
> > -	}
> > -
> >  	return page_count(page) == expected_refcount;
> >  }
> 
> mm/khugepaged.c: In function 'is_refcount_suitable':
> mm/khugepaged.c:575:25: warning: variable 'refcount set but not used [-Wunused-but-set-variable]
>   int expected_refcount, refcount;
>                          ^~~~~~~~ 
> 
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -572,9 +572,8 @@ static void release_pte_pages(pte_t *pte, pte_t *_pte,
>  
>  static bool is_refcount_suitable(struct page *page)
>  {
> -	int expected_refcount, refcount;
> +	int expected_refcount;
>  
> -	refcount = page_count(page);
>  	expected_refcount = total_mapcount(page);
>  	if (PageSwapCache(page))
>  		expected_refcount += compound_nr(page); 

Andrew, can you squash this fix?