Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757419Ab1EKQSP (ORCPT ); Wed, 11 May 2011 12:18:15 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:58544 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757402Ab1EKQSL (ORCPT ); Wed, 11 May 2011 12:18:11 -0400 Subject: Re: [tip:timers/core] timerfd: Allow timers to be cancelled when clock was set From: Peter Zijlstra To: Kay Sievers Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, johnstul@us.ibm.com, davidel@xmailserver.org, virtuoso@slind.org, tglx@linutronix.de, chris.friesen@genband.com, kirill@shutemov.name, linux-tip-commits@vger.kernel.org In-Reply-To: References: <1305109433.2914.208.camel@laptop> <1305121541.2914.213.camel@laptop> <1305122518.2914.224.camel@laptop> <1305124250.2914.225.camel@laptop> Content-Type: text/plain; charset="UTF-8" Date: Wed, 11 May 2011 16:48:53 +0200 Message-ID: <1305125333.2914.229.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1527 Lines: 33 On Wed, 2011-05-11 at 16:32 +0200, Kay Sievers wrote: > On Wed, May 11, 2011 at 16:30, Peter Zijlstra wrote: > > On Wed, 2011-05-11 at 16:22 +0200, Kay Sievers wrote: > >> On Wed, May 11, 2011 at 16:01, Peter Zijlstra wrote: > >> > On Wed, 2011-05-11 at 15:52 +0200, Kay Sievers wrote: > >> >> > >> >> No, fixed time spans have never been a problem, and are not the > >> >> example here. It's about the normal wall clock, that wakes up every > >> >> minute and updates the numbers on the screen. > >> > > >> > 'wakes up every minute' sounds like a fixed time interval to me. > >> > >> Right, but if the wall clock changes, it must not wait for the full > >> minute to update the numbers, they need to update immediately with the > >> new wall clock time. Stuff woke up every second in the past to do > >> that, but that's not what we want today. > > > > Again, nothing that couldn't be solved with a notifier of sorts. > > Right. What we have with that patch, and what's visible to the > outside, is nothing but such a notifier. What kind of interface you > have in mind instead? Dunno, an eventfd that triggers every time someone calls adjtime() and related? Anything as long as it doesn't increase HRTIMER_MAX_CLOCK_BASES really. -- 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/