Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932797Ab3IMOdE (ORCPT ); Fri, 13 Sep 2013 10:33:04 -0400 Received: from www.linutronix.de ([62.245.132.108]:36839 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757004Ab3IMOcg (ORCPT ); Fri, 13 Sep 2013 10:32:36 -0400 Date: Fri, 13 Sep 2013 16:32:24 +0200 (CEST) From: Thomas Gleixner To: Fan Du cc: David Miller , herbert@gondor.hengli.com.au, steffen.klassert@secunet.com, dborkman@redhat.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, John Stultz Subject: Re: [PATCHv3 linux-next] hrtimer: Add notifier when clock_was_set was called In-Reply-To: <52327C92.5010009@windriver.com> Message-ID: References: <20130912134409.GB21212@gondor.apana.org.au> <20130912.133252.425268707009916773.davem@davemloft.net> <52327C92.5010009@windriver.com> 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: 1162 Lines: 29 On Fri, 13 Sep 2013, Fan Du wrote: > (2) What I have been bugging you around here for this long time is really the > second > problem, I'm sorry I didn't make it clearly to you and others, which is > below: > > Why using wall clock time to calculate soft/hard IPsec events when > xfrm_state timer > out happens in its timeout handler? Because even if xfrm_state using > CLOCK_BOOTTIME, > system wall clock time changing will surely disturb soft/hard IPsec > events, which > you raised your concern about in (*a*). No CLOCK_BOOTTIME is not affected by wall clock time changes. It's basically CLOCK_MONOTONIC, it just keeps counting the suspend time as well. So without a suspend/resume cycle CLOCK_MONOTONIC and CLOCK_BOOTTIME are the same. After a suspend/resume cycle CLOCK_BOOTTIME will be N seconds ahead of CLOCK_MONOTONIC, where N is the number of seconds spent in suspend. 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/