Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750900AbWEDUCX (ORCPT ); Thu, 4 May 2006 16:02:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751331AbWEDUCX (ORCPT ); Thu, 4 May 2006 16:02:23 -0400 Received: from mail.gmx.de ([213.165.64.20]:26022 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S1750900AbWEDUCW (ORCPT ); Thu, 4 May 2006 16:02:22 -0400 X-Authenticated: #4399952 Date: Thu, 4 May 2006 22:02:22 +0200 From: Florian Paul Schmidt To: Russell King Cc: Linux Kernel List Subject: Re: sched_clock() uses are broken Message-ID: <20060504220222.53cc13f9@mango.fruits> In-Reply-To: <20060502132953.GA30146@flint.arm.linux.org.uk> References: <20060502132953.GA30146@flint.arm.linux.org.uk> X-Mailer: Sylpheed-Claws 1.0.5 (GTK+ 1.2.10; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 680 Lines: 22 On Tue, 2 May 2006 14:29:53 +0100 Russell King wrote: > However, this is not the case. On x86 with TSC, it returns a 54 bit > number. This means that when t1 < t0, time_passed_ns becomes a very > large number which no longer represents the amount of time. Hi, is this specific to the sched_clock() or does the rdtsc on these systems only use 54 bit? Flo -- Palimm Palimm! http://tapas.affenbande.org - 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/