From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 3/4] Swapping Date: Sun, 14 Oct 2007 09:46:38 +0200 Message-ID: <4711C95E.6070502@qumranet.com> References: <47102919.6070802@qumranet.com> <471124D4.3090901@codemonkey.ws> <471126D9.4030204@qumranet.com> <47112D66.4020500@qumranet.com> <47115207.3090909@codemonkey.ws> <4711542F.2060306@qumranet.com> <4711563D.8020000@codemonkey.ws> <4711B101.7070305@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Anthony Liguori Return-path: In-Reply-To: <4711B101.7070305-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Avi Kivity wrote: >>>> I wonder if there's a more elegant way dealing with older >>>> userspaces. For instance, is there any reason why we can allocate a >>>> userspace memory region on behalf of userspace. That way swap would >>>> even work with older userspaces. >>>> >>>> >>> if we can do that, yes swap will work on older userspace. >>> >>> >> I think it's just a matter of calling do_mmap() with the appropriate >> parameters. It looks likes there's some drivers call do_mmap() directly. >> >> >> > > This will halve the maximum size of virtual machines on i386 since > userspace will also mmap() the memory, and the virtual address space is > restricted to 3GB. > > Upon further reflection, considering that this will only be generally available in a kernel in six months (2.6.25) and that new userspace has already been released, and that only i386 is affected, the simplification may be worthwhile. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/