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Sun, 12 Apr 2020 00:35:19 -0700 (PDT) Received: from localhost ([43.224.245.179]) by smtp.gmail.com with ESMTPSA id f4sm6217382pjm.9.2020.04.12.00.35.18 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Sun, 12 Apr 2020 00:35:19 -0700 (PDT) Date: Sun, 12 Apr 2020 15:35:16 +0800 From: chenqiwu To: Matthew Wilcox Cc: akpm@linux-foundation.org, david@redhat.com, richard.weiyang@gmail.com, mhocko@suse.com, pankaj.gupta.linux@gmail.com, yang.shi@linux.alibaba.com, cai@lca.pw, bhe@redhat.com, linux-mm@kvack.org, chenqiwu Subject: Re: [RESEND PATCH 3/3] mm/vmscan: make several optimizations for isolate_lru_pages() Message-ID: <20200412073516.GA31142@cqw-OptiPlex-7050> References: <1586599916-15456-1-git-send-email-qiwuchen55@gmail.com> <1586599916-15456-3-git-send-email-qiwuchen55@gmail.com> <20200411161021.GD21484@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200411161021.GD21484@bombadil.infradead.org> User-Agent: Mutt/1.5.21 (2010-09-15) 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 Sat, Apr 11, 2020 at 09:10:21AM -0700, Matthew Wilcox wrote: > On Sat, Apr 11, 2020 at 06:11:56PM +0800, qiwuchen55@gmail.com wrote: > > 1) Simplify the code of initializing some variables. > > - unsigned long scan, total_scan, nr_pages; > > + unsigned long scan = 0, total_scan = 0, nr_pages; > > > > - total_scan = 0; > > - scan = 0; > > I do not find this to be a simplification. > Hi willy, This slightly simplify the code by definition and initialization meanwhile instead of separating them into the two steps. This can save two lines of code. Qiwu