Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 28 Jul 2002 17:34:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 28 Jul 2002 17:34:21 -0400 Received: from garrincha.netbank.com.br ([200.203.199.88]:15110 "HELO garrincha.netbank.com.br") by vger.kernel.org with SMTP id ; Sun, 28 Jul 2002 17:34:20 -0400 Date: Sun, 28 Jul 2002 18:36:58 -0300 (BRT) From: Rik van Riel X-X-Sender: riel@imladris.surriel.com To: Ingo Molnar cc: Andrew Morton , lkml Subject: Re: inlines in kernel/sched.c In-Reply-To: Message-ID: X-spambait: aardvark@kernelnewbies.org X-spammeplease: aardvark@nl.linux.org MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1110 Lines: 34 On Sun, 28 Jul 2002, Ingo Molnar wrote: > On Sun, 28 Jul 2002, Andrew Morton wrote: > > > Ingo, could you please review the use of inlines in the > > scheduler sometime? They seem to be excessive. > > > > For example, this patch reduces the sched.d icache footprint > > by 1.5 kilobytes. > > the patch also hurts context-switch latencies - it went > from 1.35 usecs to 1.42 usecs - a 5% drop. That's 140 cpu cycles on a 2 GHz CPU, probably less time than what a single cache miss would cost for non-scheduler-intensive workloads. This would mean that for a workload which is doing real work, and pushes the scheduler out of the L1 cache, the slowdown would be a lot more simply due to the extra cache misses the extra inlines generate. regards, Rik -- Bravely reimplemented by the knights who say "NIH". http://www.surriel.com/ http://distro.conectiva.com/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/