From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 12661900086 for ; Mon, 18 Apr 2011 20:34:19 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 72EE03EE0BB for ; Tue, 19 Apr 2011 09:34:16 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 1EC6645DE9A for ; Tue, 19 Apr 2011 09:34:16 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 005A345DE96 for ; Tue, 19 Apr 2011 09:34:16 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id DEB8E1DB804A for ; Tue, 19 Apr 2011 09:34:15 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.240.81.145]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 9C0B4E08001 for ; Tue, 19 Apr 2011 09:34:15 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH v2] mempolicy: reduce references to the current In-Reply-To: <1302847688-8076-1-git-send-email-namhyung@gmail.com> References: <1302847688-8076-1-git-send-email-namhyung@gmail.com> Message-Id: <20110419093421.9371.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 19 Apr 2011 09:34:14 +0900 (JST) Sender: owner-linux-mm@kvack.org List-ID: To: Namhyung Kim Cc: kosaki.motohiro@jp.fujitsu.com, Minchan Kim , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org > Remove duplicated reference to the 'current' task using a local > variable. Since refering the current can be a burden, it'd better > cache the reference, IMHO. At least this saves some bytes on x86_64. > > $ size mempolicy-{old,new}.o > text data bss dec hex filename > 25203 2448 9176 36827 8fdb mempolicy-old.o > 25136 2448 9184 36768 8fa0 mempolicy-new.o > > Signed-off-by: Namhyung Kim But, dense stack usage is also performance good thing. Therefore your patch benefit is not obvious. I have two request. 1) Please don't increase mess into no hot path. It's no worth. 2) Please mesure performance your box instead size command. thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org