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Date: Wed, 12 Sep 2012 23:33:47 -0700 (PDT)
From: Hugh Dickins <hughd@google.com>
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To: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
cc: Andrew Morton <akpm@linux-foundation.org>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Michel Lespinasse <walken@google.com>,
        David Rientjes <rientjes@google.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux Memory Management List <linux-mm@kvack.org>
Subject: Re: [PATCH 09/12] thp: introduce khugepaged_prealloc_page and
 khugepaged_alloc_page
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On Wed, 12 Sep 2012, Hugh Dickins wrote:
> > @@ -1825,6 +1825,7 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait)
> >  			return false;
> > 
> >  		*wait = false;
> > +		*hpage = NULL;
> >  		khugepaged_alloc_sleep();
> >  	} else if (*hpage) {
> >  		put_page(*hpage);
> 
> The unshown line just below this is
> 
> 		*hpage = NULL;
> 
> I do wish you would take the "*hpage = NULL;" out of if and else blocks
> and place it once below both.

Hold on, I'm being unreasonable: that's an "else if", and I've no good
reason to request you to set *hpage = NULL when it's already NULL.
It would be okay if you did, but there's no reason for me to prefer it.

Hugh