From owner-freebsd-questions@FreeBSD.ORG Fri Sep 21 22:02:14 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8F9A216A419 for ; Fri, 21 Sep 2007 22:02:14 +0000 (UTC) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.freebsd.org (Postfix) with ESMTP id 4338E13C455 for ; Fri, 21 Sep 2007 22:02:14 +0000 (UTC) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.14.1/8.14.1) id l8LM2DRX063685; Fri, 21 Sep 2007 17:02:13 -0500 (CDT) (envelope-from dan) Date: Fri, 21 Sep 2007 17:02:13 -0500 From: Dan Nelson To: Andreas Pettersson Message-ID: <20070921220213.GJ7562@dan.emsphone.com> References: <46F41F2D.6040503@telia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46F41F2D.6040503@telia.com> X-OS: FreeBSD 7.0-CURRENT User-Agent: Mutt/1.5.16 (2007-06-09) Cc: freebsd-questions@freebsd.org Subject: Re: top columns VCSW and IVCSW X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Sep 2007 22:02:14 -0000 In the last episode (Sep 21), Andreas Pettersson said: > I couldn't find it in the man page and Google turned up with nothing > of value so I ask here. What does the top (in IO mode) columns VCSW > and IVCSW mean? Voluntary and Involuntary context switches. Voluntary ones are usually due to syscalls that end up blocking (sleep, read, write, select etc). Involuntary ones are done by the scheduler when the process has used up its time slice or an interrupt fires. Grep the kernel for "mi_switch" to see places that switches can happen. -- Dan Nelson dnelson@allantgroup.com