Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933220Ab0HEOUT (ORCPT ); Thu, 5 Aug 2010 10:20:19 -0400 Received: from exprod7og118.obsmtp.com ([64.18.2.8]:57753 "EHLO exprod7og118.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755476Ab0HEOUP (ORCPT ); Thu, 5 Aug 2010 10:20:15 -0400 Message-ID: <4C5AC646.9010403@genband.com> Date: Thu, 05 Aug 2010 08:10:14 -0600 From: Chris Friesen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.9) Gecko/20100430 Fedora/3.0.4-2.fc11 Thunderbird/3.0.4 MIME-Version: 1.0 To: john stultz CC: Alexander Shishkin , gregkh@suse.de, lkml@vger.kernel.org, "Kirill A. Shutemov" , Thomas Gleixner , Martin Schwidefsky , Andrew Morton , Jon Hunter , Ingo Molnar , Peter Zijlstra , "Paul E. McKenney" , David Howells , Avi Kivity , "H. Peter Anvin" , John Kacur , linux-kernel@vger.kernel.org Subject: Re: [PATCH] [RFC] notify userspace about time changes References: <1280926108-24668-1-git-send-email-virtuoso@slind.org> <1280937526.28884.21.camel@work-vm> <4C59B5E1.9040707@genband.com> <1280969546.2678.33.camel@localhost.localdomain> In-Reply-To: <1280969546.2678.33.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 05 Aug 2010 14:10:17.0039 (UTC) FILETIME=[EE2E5DF0:01CB34A7] X-TM-AS-Product-Ver: SMEX-8.0.0.4160-6.500.1024-17550.007 X-TM-AS-Result: No--21.957200-5.000000-31 X-TM-AS-User-Approved-Sender: No X-TM-AS-User-Blocked-Sender: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1354 Lines: 35 On 08/04/2010 06:52 PM, john stultz wrote: > On Wed, 2010-08-04 at 12:48 -0600, Chris Friesen wrote: >> On 08/04/2010 09:58 AM, john stultz wrote: >> >>> Is there a actual use case that you need this for? I don't really have >>> an issue with the code I just really want to make sure the feature would >>> be useful enough to justify the API and code maintenance going forward. >> >> We actually added a time-change-notification mechanism internally a long >> time ago but never saw demand for it and so never bothered trying to >> push it upstream. Ours is signal-based. >> >> Among other things we use it to pass on time-change notifications to an >> emulator running a proprietary OS that really cares about having an >> accurate time-of-day but can't afford a syscall to retrieve it every time. > > So the eventfd based method (and the filtering) proposed would work for > you? The eventfd based method would work. The filtering is unnecessary for us and seems somewhat fragile as currently implemented. Chris -- Chris Friesen Software Developer GENBAND chris.friesen@genband.com www.genband.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/