Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932636AbVISXMP (ORCPT ); Mon, 19 Sep 2005 19:12:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932646AbVISXMP (ORCPT ); Mon, 19 Sep 2005 19:12:15 -0400 Received: from 213-239-205-147.clients.your-server.de ([213.239.205.147]:10966 "EHLO mail.tglx.de") by vger.kernel.org with ESMTP id S932636AbVISXMP (ORCPT ); Mon, 19 Sep 2005 19:12:15 -0400 Subject: Re: [ANNOUNCE] ktimers subsystem From: Thomas Gleixner Reply-To: tglx@linutronix.de To: Christoph Lameter Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, akpm@osdl.org, george@mvista.com, johnstul@us.ibm.com, paulmck@us.ibm.com In-Reply-To: References: <20050919184834.1.patchmail@tglx.tec.linutronix.de> <1127168232.24044.265.camel@tglx.tec.linutronix.de> <1127169849.24044.279.camel@tglx.tec.linutronix.de> Content-Type: text/plain Organization: linutronix Date: Tue, 20 Sep 2005 01:12:22 +0200 Message-Id: <1127171542.24044.301.camel@tglx.tec.linutronix.de> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1438 Lines: 39 On Mon, 2005-09-19 at 16:04 -0700, Christoph Lameter wrote: > On Tue, 20 Sep 2005, Thomas Gleixner wrote: > > > Hmm. I don't understand the argument line completely. > > > > 1. The kernel has to provide ugly mechanisms because a lot of > > applications implementations are doing the Wrong Thing ? > > Lets skip the "wrong thing"... Or are you saying that glibc and all the > apps are all wrong? > > Applications call gettimeofday for a variety of reasons. One is because it > is widely available over different platformsn and application want to > schedule things, need timestamps etc etc. Accepted. But I still doubt that the number of calls to gettimeofday is in anyway justified. The question I'm asking if it is really worth a long and epic discussion about a single add instruction ? > > > Many platforms can execute gettimeofday > > > without having to enter the kernel. > > > > Which ones ? How is this achieved with respect to all the time adjust, > > correction... code ? > > IA64 f.e. has a special instruction that allows access to kernel user > space without having to do a context switch. Ok, was not aware of that and John kindly clarified this already. 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/