From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755157AbYIDQWx (ORCPT ); Thu, 4 Sep 2008 12:22:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751896AbYIDQWp (ORCPT ); Thu, 4 Sep 2008 12:22:45 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:48311 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751404AbYIDQWo (ORCPT ); Thu, 4 Sep 2008 12:22:44 -0400 Date: Thu, 4 Sep 2008 09:21:42 -0700 (PDT) From: Linus Torvalds To: Ingo Molnar cc: Thomas Gleixner , LKML , Alok Kataria , Arjan van de Veen , "H. Peter Anvin" , Peter Zijlstra Subject: Re: [RFC patch 0/4] TSC calibration improvements In-Reply-To: <20080904160036.GA18382@elte.hu> Message-ID: References: <20080904150339.896115280@linutronix.de> <20080904153620.GC7120@elte.hu> <20080904160036.GA18382@elte.hu> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 4 Sep 2008, Ingo Molnar wrote: > > ah - perhaps a dynamic statistical approach with an estimation of > worst-case calibration error (~= standard deviation) and a quality > threshold to reach? That could dramatically increase the number of > samples while also making it much faster in practice. Nifty! Oh, no, I'm _much_ more nifty than that! Instead of being very clever, I have a very _stupid_ algorithm, one that has very hardcoded expectations of exactly what it will see. And if it doesn't see exactly that, it just fails early. I'd post the patch, but I really need to actually _test_ it first, and I haven't rebooted yet. Linus