From owner-cvs-src@FreeBSD.ORG Mon Aug 9 21:47:03 2004 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from green.homeunix.org (freefall.freebsd.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id 34C1216A4CE; Mon, 9 Aug 2004 21:47:03 +0000 (GMT) Received: from green.homeunix.org (green@localhost [127.0.0.1]) by green.homeunix.org (8.12.11/8.12.11) with ESMTP id i79Ll2D3078740; Mon, 9 Aug 2004 17:47:02 -0400 (EDT) (envelope-from green@green.homeunix.org) Received: (from green@localhost) by green.homeunix.org (8.13.1/8.13.1/Submit) id i79Ll2er078734; Mon, 9 Aug 2004 17:47:02 -0400 (EDT) (envelope-from green) Date: Mon, 9 Aug 2004 17:47:01 -0400 From: Brian Fundakowski Feldman To: Andrew Gallatin Message-ID: <20040809214701.GE14657@green.homeunix.org> References: <200408091952.i79JqT4B076245@repoman.freebsd.org> <20040809165215.A84463@grasshopper.cs.duke.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040809165215.A84463@grasshopper.cs.duke.edu> User-Agent: Mutt/1.5.6i cc: cvs-src@FreeBSD.org cc: src-committers@FreeBSD.org cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/vm vm_kern.c vm_map.c vm_map.h X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 Aug 2004 21:47:03 -0000 On Mon, Aug 09, 2004 at 04:52:15PM -0400, Andrew Gallatin wrote: > Brian Feldman [green@FreeBSD.org] wrote: > > > * Require all mappings to be unwired before they are deleted. > > When VM space is still wired upon deletion, it will be waited > > upon for the following unwire. This makes vslock(9) work > > rather than allowing kernel-locked memory to be deleted > > out from underneath of its consumer as it would before. > > Can you explain in a little more detail what would happen now in the > following scenario: > > An application running in userspace allocates SIZE bytes at "addr", > either with an mmap or via sbrk. Then something in the kernel calls: > vm_map_wire(map, addr, addr + SIZE, TRUE) on its behalf. > Then the application frees (or munmaps) "addr". > > Does the application sleep waiting for something to unwire addr+SIZE? Yes, that is exactly what happens (replace TRUE with appropriate current flags); is there some other behavior you would expect to see? -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green@FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\