Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754206AbXFZAWu (ORCPT ); Mon, 25 Jun 2007 20:22:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752565AbXFZAWl (ORCPT ); Mon, 25 Jun 2007 20:22:41 -0400 Received: from rtr.ca ([64.26.128.89]:4562 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752244AbXFZAWl (ORCPT ); Mon, 25 Jun 2007 20:22:41 -0400 Message-ID: <46805C4F.1050200@rtr.ca> Date: Mon, 25 Jun 2007 20:22:39 -0400 From: Mark Lord User-Agent: Thunderbird 2.0.0.4 (X11/20070604) MIME-Version: 1.0 To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Andrew Morton , John Stultz , Thomas Gleixner Subject: Re: [patch, v2.6.22-rc6] sys_time() speedup References: <20070625200601.GA18980@elte.hu> In-Reply-To: <20070625200601.GA18980@elte.hu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 815 Lines: 21 Ingo Molnar wrote: > Subject: [patch] sys_time() speedup > From: Ingo Molnar > > improve performance of sys_time(). sys_time() returns time in seconds, > but it does so by calling do_gettimeofday() and then returning the > tv_sec portion of the GTOD time. But the data structure "xtime", which > is updated by every timer/scheduler tick, already offers HZ granularity > time. How well synchronized is xtime with real-time ? Programs invoking sys_time() do expect it to be as accurate as gettimeofday(), even if only at 1-second boundaries. Cheers - 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/