From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751374AbWCDHR0 (ORCPT ); Sat, 4 Mar 2006 02:17:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751405AbWCDHR0 (ORCPT ); Sat, 4 Mar 2006 02:17:26 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:14491 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S1751374AbWCDHRZ (ORCPT ); Sat, 4 Mar 2006 02:17:25 -0500 Date: Sat, 4 Mar 2006 08:15:10 +0100 From: Ingo Molnar To: john stultz Cc: lkml , Andrew Morton , tglx@linutronix.de, zippel@linux-m68k.org, rmk@arm.linux.org.uk, schwidefsky@de.ibm.com, tony.luck@intel.com, davidm@hpl.hp.com, clameter@sgi.com, george@mvista.com, ak@suse.de, paulus@samba.org, benh@kernel.crashing.org, arnd@arndb.de Subject: Re: [RFC][PATCHSET] Time: Generic Timeofday Subsystem (v B20) Message-ID: <20060304071510.GA3893@elte.hu> References: <1141447396.9727.139.camel@cog.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1141447396.9727.139.camel@cog.beaverton.ibm.com> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL autolearn=no SpamAssassin version=3.0.3 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * john stultz wrote: > Summary: > This patchset provides a generic timekeeping subsystem that is > independent of the timer interrupt. This allows for robust and correct > behavior in cases of late or lost ticks, avoids interpolation errors, > reduces duplication in arch specific code, and allows or assists > future changes such as high-res timers, dynamic ticks, or realtime > preemption. Additionally, it provides finer nanosecond resolution > values to the clock_gettime functions. > > Why do we need this? i'd like to add the following to the list of reasons as well: the current -hrt patch-queue (high resolution timers, which enables true microsecond-level resolution for POSIX timers and nanosleep()), which is working pretty well in the -rt tree and implements an important feature for Linux, is based on the generic timekeeping subsystem as well. Ingo