From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264558AbTK0Qq3 (ORCPT ); Thu, 27 Nov 2003 11:46:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264561AbTK0Qq3 (ORCPT ); Thu, 27 Nov 2003 11:46:29 -0500 Received: from 5.86.35.65.cfl.rr.com ([65.35.86.5]:14210 "EHLO drunkencodepoets.com") by vger.kernel.org with ESMTP id S264558AbTK0Qq2 (ORCPT ); Thu, 27 Nov 2003 11:46:28 -0500 Date: Thu, 27 Nov 2003 11:46:31 -0500 From: Pat Erley To: Muli Ben-Yehuda Cc: linux-kernel@vger.kernel.org Subject: Re: [patch] trivial change in kernel/sched.c in 2.6.0-test9+ Message-Id: <20031127114631.06f71eb7.paterley@mail.drunkencodepoets.com> In-Reply-To: <20031126110250.GB27967@actcom.co.il> References: <20031126002713.1f8707f8.paterley@mail.drunkencodepoets.com> <20031126055556.GC3734@actcom.co.il> <20031126010701.25600adb.s0be@mail.drunkencodepoets.com> <20031126110250.GB27967@actcom.co.il> Organization: drunkencodepoets.com X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > If you can suggest a way to test this, I will test it on my system > > tomorrow. > > Just off the top of my head, you could try something like a kernel > compilation with and without it. I doubt you'll see any improvement, > though.. there are very few places in the kernel where such > micro-optimizations are worth it, IMVHO. Well, I ran about 6 different compiles each on a patched and an unpatched, and my 'average' savings were about 1 second per 6 minute compile, which is negligible. I wonder if doing a make is a good test of this. Can anyone else out there come up with another way to check this with a non-cpu hog application? I'd like some other cases to test this in. I mean, when you do a 'large' number of compiles that each take a half second, I can see that saving a division and an addition really wouldn't make a big difference, but in a situation where you have a large number of short lived threads in a child process, it may end up saving a bit more. Pat Erley