Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756875Ab0KKUv0 (ORCPT ); Thu, 11 Nov 2010 15:51:26 -0500 Received: from filtteri1.pp.htv.fi ([213.243.153.184]:54484 "EHLO filtteri1.pp.htv.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756728Ab0KKUvZ (ORCPT ); Thu, 11 Nov 2010 15:51:25 -0500 Date: Thu, 11 Nov 2010 22:51:23 +0200 From: Alexander Shishkin To: Valdis.Kletnieks@vt.edu Cc: linux-kernel@vger.kernel.org, John Stultz , Andrew Morton , "H. Peter Anvin" , Kay Sievers , Greg KH , Chris Friesen , Linus Torvalds , "Kirill A. Shutemov" , Thomas Gleixner , Alexander Shishkin Subject: Re: [PATCHv6 0/7] system time changes notification Message-ID: <20101111205123.GC10585@shisha.kicks-ass.net> References: <1289503802-22444-1-git-send-email-virtuoso@slind.org> <22542.1289507293@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <22542.1289507293@localhost> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1322 Lines: 30 On Thu, Nov 11, 2010 at 03:28:13PM -0500, Valdis.Kletnieks@vt.edu wrote: > On Thu, 11 Nov 2010 21:29:55 +0200, Alexander Shishkin said: > > > Consider we want stuff like "wakeup every day at 3pm", the next wakeup > > might be earlier than the timer we calculated last time, on system > > time changes. We need to re-calculate it. This is necessary for all > > repeating events. > > > > Say we want to wakeup at 3pm, now it's 4pm, so we schedule it in 23 > > hours. Now the system time changes to 2pm, and we would expect to > > wakeup in one hour, but we take 25. > > Sorry, I tuned in late here... > > So the plan is that if you're not using this new interface, it will go off at > the same absolute offset (23 hours after timer was set), but if you're using > this interface, your timer event gets interrupted, you get woken up (say) > 15 hours into your 23, and it's your job to decide if you need to set a > new timer for the remaining 6, 7, 8 hours or some other number? Yes. This interface doesn't deal with timers, it only provides notifications. Regards, -- Alex -- 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/