Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757102Ab3ILUfK (ORCPT ); Thu, 12 Sep 2013 16:35:10 -0400 Received: from mail-ie0-f170.google.com ([209.85.223.170]:35252 "EHLO mail-ie0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755618Ab3ILUfG (ORCPT ); Thu, 12 Sep 2013 16:35:06 -0400 MIME-Version: 1.0 In-Reply-To: <20130912134409.GB21212@gondor.apana.org.au> 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> Date: Thu, 12 Sep 2013 13:35:02 -0700 X-Google-Sender-Auth: iJ8vabj4WWavN9x3N6okU_rkywc Message-ID: Subject: Re: [PATCHv3 linux-next] hrtimer: Add notifier when clock_was_set was called From: John Stultz To: Herbert Xu Cc: Thomas Gleixner , Fan Du , Steffen Klassert , David Miller , Daniel Borkmann , LKML , netdev Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1441 Lines: 35 On Thu, Sep 12, 2013 at 6:44 AM, 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 > AFAIK does not touch normal timers. I'm not sure I've totally groked the specific need here, but if you're wanting a monotonic clockbase that includes suspend time, then you might checkout CLOCK_BOOTTIME. thanks -john -- 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/