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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: <20190807052858.GA9749@mypc> References: <1565078411-27082-1-git-send-email-kernelfans@gmail.com> <20190806133503.GC30179@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190806133503.GC30179@bombadil.infradead.org> User-Agent: Mutt/1.11.3 (2019-02-01) 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: On Tue, Aug 06, 2019 at 06:35:03AM -0700, Matthew Wilcox wrote: > > 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); > + > This makes code better. Thank you for the suggestion. Will send v2 for this patch. Regards, Pingfan