From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756776Ab0E1NnL (ORCPT ); Fri, 28 May 2010 09:43:11 -0400 Received: from bar.sig21.net ([80.81.252.164]:39232 "EHLO bar.sig21.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756728Ab0E1NnG (ORCPT ); Fri, 28 May 2010 09:43:06 -0400 Date: Fri, 28 May 2010 15:42:33 +0200 From: Johannes Stezenbach To: Peter Zijlstra Cc: Andrew Morton , Jens Axboe , Divyesh Shah , Ingo Molnar , LKML Subject: Re: [PATCH] sched_clock: Provide local_clock() and improve documentation Message-ID: <20100528134233.GA28190@sig21.net> References: <4BF9EC69.5030709@example.com> <1274777422.5882.591.camel@twins> <20100526160252.325f8357.akpm@linux-foundation.org> <1274942798.27810.3584.camel@twins> <20100526235107.77e66ce0.akpm@linux-foundation.org> <1274945751.27810.3765.camel@twins> <20100527113340.d4afb8fc.akpm@linux-foundation.org> <1275052414.1645.52.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1275052414.1645.52.camel@laptop> User-Agent: Mutt/1.5.20 (2009-06-14) X-Spam-21-Score: -3.7 (---) X-Spam-21-Report: No, score=-3.7 required=5.0 tests=ALL_TRUSTED=-1.8,AWL=0.711,BAYES_00=-2.599 autolearn=no Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 28, 2010 at 03:13:34PM +0200, Peter Zijlstra wrote: > + * The !IRQ-safetly of sched_clock() and sched_clock_cpu() comes from things typo ^ Thank you for adding documentation. I have one additional question regarding wrapping of sched_clock(). I know it is used for timestamps in ftrace and printk, so it's desirable that it never wraps. But on several embedded systems it wraps after a few hours. Bug or just a minor flaw? If someone knows it would be nice to get that documented, too. See also http://lkml.org/lkml/2010/4/26/340 Johannes