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[209.132.180.67]) by mx.google.com with ESMTP id 1si14733280pln.308.2019.08.21.04.24.27; Wed, 21 Aug 2019 04:24:43 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=I6B98DFn; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727134AbfHULUp (ORCPT + 99 others); Wed, 21 Aug 2019 07:20:45 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:43043 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726462AbfHULUp (ORCPT ); Wed, 21 Aug 2019 07:20:45 -0400 Received: by mail-pl1-f194.google.com with SMTP id 4so1165282pld.10 for ; Wed, 21 Aug 2019 04:20:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=sj3vybXlMQvoxOUao0lktce4iPTDPPDmKNm+ajxk4V8=; b=I6B98DFnHujHQRvScmKkTNQY/o0aPuSa3GXtxYHjX+adoN//FqCUcVSxhNV91lcj3X lMy3WtpEhhxi7MCEYfUxPbJHkzc+KE24cPGttnEqcKiD8H2z33nJ0Q7BBauJf11ufcoG X9GpedEX3o5N+I7Epw1Tqydnkzkj3kFMFNPE1HeNC4QIQdRB3EYd9WQmDZUl1Yclisqe VbeUSL+fTpxFAjVuXNA/DO2aHBBy4ecq7IINPGanWffC19pBXkxu7UfMbcLjcVMRc9PB qCYfi9TIj5G0kkoKpUpAmizaT+mLRI024X+lDqS3lCMZBB5pEibQQpQitG1mMnlF9UOw q29A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=sj3vybXlMQvoxOUao0lktce4iPTDPPDmKNm+ajxk4V8=; b=BczYIoZID5d76K8Y4aSZ9MxS4IEYJIU754niq18G9GZARMQJ9C/VzyCHUjzR52hapo q3jcTuscGgESRlJU/DP3oAXCiN/77F4/hBCPDhTbXx7VSxE8GbptfXI2zxz2cklPYZnV cpwV8TxijnzBSVZpszCeDa6cIMYL8Nnw5RodUQ3GZfMMNOKFWQ6JwpFlPeuWJ6MEeyyb 8YVnpBLuIgNM3y+SdE5/z4qTWBBC2QYoI5y3RbLGLZmlFKtZFehj6f53twxeA8hM938W TSj7EJkxJ8jhfS/7WBwRH8T4nB5MOXSt726faR05eWzt1qjeS9zIyOUEClK9ZGweQNCE WZeQ== X-Gm-Message-State: APjAAAVj0n3k7I0sMLWicdJdrAoqDKn6rAUMYa6DpvRJF0qFvMOM+9uf 8dZ7rVv5h3jAuFSOAb6ueM9dxCqC X-Received: by 2002:a17:902:110b:: with SMTP id d11mr7155736pla.84.1566386444549; Wed, 21 Aug 2019 04:20:44 -0700 (PDT) Received: from iZj6chx1xj0e0buvshuecpZ ([47.75.1.235]) by smtp.gmail.com with ESMTPSA id w26sm27216990pfq.100.2019.08.21.04.20.42 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 21 Aug 2019 04:20:43 -0700 (PDT) Date: Wed, 21 Aug 2019 19:20:40 +0800 From: Peng Liu To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, mingo@redhat.com Subject: Re: [PATCH] sched/fair: eliminate redundant code in sched_slice() Message-ID: <20190821112040.GA32150@iZj6chx1xj0e0buvshuecpZ> References: <20190816141202.GA3135@iZj6chx1xj0e0buvshuecpZ> <20190820135055.GR2332@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190820135055.GR2332@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 20, 2019 at 03:50:55PM +0200, Peter Zijlstra wrote: > On Fri, Aug 16, 2019 at 10:12:02PM +0800, Peng Liu wrote: > > Since sched_slice() is used in high frequency, > > small change should also make sense. > > An actual Changelog would also make sense; but alas. Thanks for your time! About the changelog, I admit that it makes little improvement to the whole, It is a so *short* function, I also don't think it can produce any visible improvement through any kernel test tools. But as you can see, the redundant intermediate operation indeed exists. There's no reason to let it exist any more - make code clear and easy to understand if possible. Best Regards, Liu