From owner-freebsd-stable@FreeBSD.ORG  Mon Nov 19 18:46:41 2007
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 0222116A46E;
	Mon, 19 Nov 2007 18:46:41 +0000 (UTC)
	(envelope-from kris@FreeBSD.org)
Received: from weak.local (freefall.freebsd.org [IPv6:2001:4f8:fff6::28])
	by mx1.freebsd.org (Postfix) with ESMTP id 24AC813C4E3;
	Mon, 19 Nov 2007 18:46:39 +0000 (UTC)
	(envelope-from kris@FreeBSD.org)
Message-ID: <4741DA15.9000308@FreeBSD.org>
Date: Mon, 19 Nov 2007 19:46:45 +0100
From: Kris Kennaway <kris@FreeBSD.org>
User-Agent: Thunderbird 2.0.0.9 (Macintosh/20071031)
MIME-Version: 1.0
To: Alexey Popov <lol@chistydom.ru>
References: <4741905E.8050300@chistydom.ru>	<fhs3s5$knj$1@ger.gmane.org>	<47419AB3.5030008@chistydom.ru>	<fhs7hp$2es$2@ger.gmane.org>
	<4741A7DA.2050706@chistydom.ru>
In-Reply-To: <4741A7DA.2050706@chistydom.ru>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Cc: freebsd-stable@freebsd.org, Ivan Voras <ivoras@freebsd.org>
Subject: Re: 2 x quad-core system is slower that 2 x dual core on FreeBSD
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 19 Nov 2007 18:46:41 -0000

Alexey Popov wrote:
> Hi.
> 
> Ivan Voras wrote:
>>> CPU states:  9.5% user,  0.0% nice, 82.0% system,  0.5% interrupt,  8.0%
>>> idle
>> A wild idea that might not help: try reducing kern.hz in loader.conf to
>> something like 100 and see if something significant changes.
> Now it runs with hz=100, number of context switches became ~ 2 times
> less, but still there's 90% system CPU load (see attach).

System CPU usage doesn't tell you anything by itself, you need to look 
at how much work the system is actually doing (pages served/second, or 
whatever).  For example, when your kernel is getting more work done, 
system CPU usage will also be higher.

Kris