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[2607:7c80:54:e::133]) by mx.google.com with ESMTPS id o63si15028780pjo.94.2019.08.06.06.35.05 for (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 06 Aug 2019 06:35:05 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of willy@infradead.org designates 2607:7c80:54:e::133 as permitted sender) client-ip=2607:7c80:54:e::133; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=bombadil.20170209 header.b=dfTE8QFW; spf=pass (google.com: best guess record for domain of willy@infradead.org designates 2607:7c80:54:e::133 as permitted sender) smtp.mailfrom=willy@infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=LSrTDhsJpuHztoZ1vcQuO446UAhMwmMAYnYunQdQJVw=; b=dfTE8QFWDKasKNrl8PXCKENnA IsKrDnUGP/zpSEhJ0QG5ygHuuJTq3B7DlBi+/eJWeBsvzw8dnTtST1kAD3YyRToBtRJP58aeFUkiB 3+HRTgVlp4K8xeDLEison7I8LUYJzN3p7U7CWFDZb7K/qvO/C8zZRSiIQHkz+hR0W88uBNtqkGpe1 Ppo6E5ronvOPCj5A8eBSS4I6gwTQ6BRzRzAeoXB2LvkUug8dmGHFuyFsE1IBOgJAViCJagElvFJgJ iAMHMYibhwEkKHFLQBQdjiRlRVhKF2doWfHNqHwVh8YNPrflGEylFt9NBAx6TV5/ZlXTEVvfpBxWM VFYR7EQTA==; Received: from willy by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1huzcF-0005L9-Op; Tue, 06 Aug 2019 13:35:03 +0000 Date: Tue, 6 Aug 2019 06:35:03 -0700 From: Matthew Wilcox To: Pingfan Liu Cc: linux-mm@kvack.org, =?iso-8859-1?B?Suly9G1l?= Glisse , Andrew Morton , Mel Gorman , Jan Kara , "Kirill A. Shutemov" , Michal Hocko , Mike Kravetz , Andrea Arcangeli , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] mm/migrate: clean up useless code in migrate_vma_collect_pmd() Message-ID: <20190806133503.GC30179@bombadil.infradead.org> References: <1565078411-27082-1-git-send-email-kernelfans@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1565078411-27082-1-git-send-email-kernelfans@gmail.com> User-Agent: Mutt/1.11.4 (2019-03-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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) > 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); +