From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1FUEPt-0001hr-CJ for user-mode-linux-devel@lists.sourceforge.net; Thu, 13 Apr 2006 19:52:13 -0700 Received: from [198.99.130.12] (helo=saraswathi.solana.com) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1FUEPr-0002jT-5H for user-mode-linux-devel@lists.sourceforge.net; Thu, 13 Apr 2006 19:52:13 -0700 From: Jeff Dike Subject: Re: [uml-devel] Re: [RFC] PATCH 0/4 - Time virtualization Message-ID: <20060414015316.GA7723@ccure.user-mode-linux.org> References: <200604131719.k3DHJcZG004674@ccure.user-mode-linux.org> <1144974688.8548.26.camel@cog.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1144974688.8548.26.camel@cog.beaverton.ibm.com> Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Thu, 13 Apr 2006 21:53:16 -0400 To: john stultz Cc: linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net On Thu, Apr 13, 2006 at 05:31:27PM -0700, john stultz wrote: > Looks interesting. I've never quite understood the need for different > time domains, it only allows you to run one domain with the incorrect > time, but I'm sure there is some use case that is desired. There are a few possible answers - If when this virtualization stuff is done, no one has done anything with time, someone is going to moan. Once in a while, you want to fiddle your system clock to make sure that a cron job or something does what it's supposed to. There was some extra infrastructure that UML needed in order to start using this stuff, so I chose a fairly simple virtualization case to accompany it. > I'm not psyched about possible namespace vs nanosecond confusion w/ > terms like "time_ns", but that's pretty minor. Yeah, names can be changed. > Also I hope you're not wanting to deal w/ NTP adjustments between > domains that have the incorrect time? That would be very ugly. No, the domain stores an offset from the system time, so it automatically gets the system's NTP adjustments. Jeff ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751177AbWDNCwm (ORCPT ); Thu, 13 Apr 2006 22:52:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751215AbWDNCwm (ORCPT ); Thu, 13 Apr 2006 22:52:42 -0400 Received: from saraswathi.solana.com ([198.99.130.12]:4509 "EHLO saraswathi.solana.com") by vger.kernel.org with ESMTP id S1751177AbWDNCwl (ORCPT ); Thu, 13 Apr 2006 22:52:41 -0400 Date: Thu, 13 Apr 2006 21:53:16 -0400 From: Jeff Dike To: john stultz Cc: linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net Subject: Re: [uml-devel] Re: [RFC] PATCH 0/4 - Time virtualization Message-ID: <20060414015316.GA7723@ccure.user-mode-linux.org> References: <200604131719.k3DHJcZG004674@ccure.user-mode-linux.org> <1144974688.8548.26.camel@cog.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1144974688.8548.26.camel@cog.beaverton.ibm.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 13, 2006 at 05:31:27PM -0700, john stultz wrote: > Looks interesting. I've never quite understood the need for different > time domains, it only allows you to run one domain with the incorrect > time, but I'm sure there is some use case that is desired. There are a few possible answers - If when this virtualization stuff is done, no one has done anything with time, someone is going to moan. Once in a while, you want to fiddle your system clock to make sure that a cron job or something does what it's supposed to. There was some extra infrastructure that UML needed in order to start using this stuff, so I chose a fairly simple virtualization case to accompany it. > I'm not psyched about possible namespace vs nanosecond confusion w/ > terms like "time_ns", but that's pretty minor. Yeah, names can be changed. > Also I hope you're not wanting to deal w/ NTP adjustments between > domains that have the incorrect time? That would be very ugly. No, the domain stores an offset from the system time, so it automatically gets the system's NTP adjustments. Jeff