Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753932Ab3ILOns (ORCPT ); Thu, 12 Sep 2013 10:43:48 -0400 Received: from www.linutronix.de ([62.245.132.108]:59048 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751034Ab3ILOnr (ORCPT ); Thu, 12 Sep 2013 10:43:47 -0400 Date: Thu, 12 Sep 2013 16:43:37 +0200 (CEST) From: Thomas Gleixner To: Herbert Xu cc: Fan Du , Steffen Klassert , David Miller , Daniel Borkmann , LKML , netdev Subject: Re: [PATCHv3 linux-next] hrtimer: Add notifier when clock_was_set was called In-Reply-To: <20130912134409.GB21212@gondor.apana.org.au> Message-ID: References: <1375866296-15079-1-git-send-email-fan.du@windriver.com> <1375866296-15079-2-git-send-email-fan.du@windriver.com> <52021177.6020306@redhat.com> <520213F2.5090401@windriver.com> <520214C6.6000307@redhat.com> <520B4552.2000607@windriver.com> <5212CCCA.4090907@windriver.com> <20130912134409.GB21212@gondor.apana.org.au> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1834 Lines: 48 On Thu, 12 Sep 2013, Herbert Xu wrote: > On Thu, Sep 12, 2013 at 03:21:24PM +0200, Thomas Gleixner wrote: > > > > > (3): http://www.spinics.net/lists/netdev/msg245169.html > > > > Thanks for the explanation so far. > > > > What's still unclear to me is why these timeouts are bound to wall > > time in the first place. > > > > Is there any real reason why the key life time can't simply be > > expressed in monotonic time, e.g. N seconds after creation or M > > seconds after usage? Looking at the relevant RFCs I can't find any > > requirement for binding the life time to wall time. > > > > A life time of 10 minutes does not change when the wall clock is > > adjusted for whatever reasons. It's still 10 minutes and not some > > random result of the wall clock adjustments. But I might be wrong as > > usual :) > > Well we started out with straight timers. It was changed because > people wanted IPsec SAs to expire after a suspect/resume which Right suspend is the usual suspect :) > AFAIK does not touch normal timers. > > Of course, this brought with it a new set of problems when the > system time is stepped which now cause SAs to expire even though > they probably shouldn't. Right. That's what I guessed. So your problem is that the timer_list timers which are the proper mechanism for this (the life time has a 1 second granularity, so hrtimers are complete overkill) are not expiring after a suspend/resume cycle. So what about going back to timer_list timers and simply utilize register_pm_notifier(), which will tell you that the system resumed? Thanks, tglx -- 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/