From owner-freebsd-hackers@FreeBSD.ORG Wed Oct 8 19:11:11 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3AF1E106568A for ; Wed, 8 Oct 2008 19:11:11 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from server.baldwin.cx (bigknife-pt.tunnel.tserv9.chi1.ipv6.he.net [IPv6:2001:470:1f10:75::2]) by mx1.freebsd.org (Postfix) with ESMTP id D0EBA8FC12 for ; Wed, 8 Oct 2008 19:11:10 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from localhost.corp.yahoo.com (john@localhost [IPv6:::1]) (authenticated bits=0) by server.baldwin.cx (8.14.2/8.14.2) with ESMTP id m98JB4tU057790; Wed, 8 Oct 2008 15:11:04 -0400 (EDT) (envelope-from jhb@freebsd.org) From: John Baldwin To: freebsd-hackers@freebsd.org Date: Wed, 8 Oct 2008 14:06:14 -0400 User-Agent: KMail/1.9.7 References: <53fa490b0810071947j23fc0f72n5360b6f174ddc96d@mail.gmail.com> In-Reply-To: <53fa490b0810071947j23fc0f72n5360b6f174ddc96d@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200810081406.14916.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [IPv6:::1]); Wed, 08 Oct 2008 15:11:05 -0400 (EDT) X-Virus-Scanned: ClamAV 0.93.1/8395/Wed Oct 8 12:44:51 2008 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.4 required=4.2 tests=AWL,BAYES_00,NO_RELAYS autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: ushasri tummala Subject: Re: What is the time between 2 mi_switches in freebsd. X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 Oct 2008 19:11:11 -0000 On Tuesday 07 October 2008 10:47:16 pm ushasri tummala wrote: > What is the time between 2 mi_switches in freebsd?In which variable is this > information stored? > > Could you plz help me out with this There isn't a fixed timeslice due to preemption for interrupts, etc. However, the default time slice is available as the kern.sched.quantum sysctl: % sysctl -d kern.sched.quantum kern.sched.quantum: Roundrobin scheduling quantum in microseconds In the kernel it is stored as a static (private) variable in the scheduler implementation. -- John Baldwin