Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754657AbXLNOhs (ORCPT ); Fri, 14 Dec 2007 09:37:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752882AbXLNOhl (ORCPT ); Fri, 14 Dec 2007 09:37:41 -0500 Received: from nf-out-0910.google.com ([64.233.182.184]:22892 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752681AbXLNOhk (ORCPT ); Fri, 14 Dec 2007 09:37:40 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding:from; b=e/C/q5hjcf+oXUADY7FjasaLQstrcunmBGfiPNQNxsK7UrG+bM/aJ+89lQXwKDV0XbzGvbIlbLsa44n2T8qdycuc9qkVB9r6AWCKf/WaIunEas/Ln54lDvnozOVjirzV2HJXzOPS9+NFkNkGWUiVXfBpTt6HTXQGo7t5PEBO2XA= Message-ID: <476294D3.4060609@keyaccess.nl> Date: Fri, 14 Dec 2007 15:36:03 +0100 User-Agent: Thunderbird 2.0.0.9 (X11/20071031) MIME-Version: 1.0 To: Ingo Molnar CC: Rene Herman , "David P. Reed" , Alan Cox , Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar , "H. Peter Anvin" , Pavel Machek Subject: Re: [PATCH] x86_64: fix problems due to use of "outb" to port 80 on some AMD64x2 laptops, etc. References: <1181682498.8176.224.camel@chaos> <469578CD.3080609@reed.com> <1184216528.12353.203.camel@chaos> <1184218962.12353.209.camel@chaos> <46964352.7040301@reed.com> <1184253339.12353.223.camel@chaos> <469697C6.50903@reed.com> <1184274754.12353.254.camel@chaos> <4761F193.7090400@reed.com> <476250D5.8000409@gmail.com> <20071214142355.GA10130@elte.hu> In-Reply-To: <20071214142355.GA10130@elte.hu> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit From: Rene Herman Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1251 Lines: 35 On 14-12-07 15:23, Ingo Molnar wrote: > * Rene Herman wrote: > >> --- a/init/main.c >> +++ b/init/main.c >> @@ -229,10 +229,9 @@ static int __init obsolete_checksetup(char *line) >> } >> >> /* >> - * This should be approx 2 Bo*oMips to start (note initial shift), and will >> - * still work even if initially too large, it will just take slightly longer >> + * Initial value roughly corresponds to a 1 GHz CPU >> */ >> -unsigned long loops_per_jiffy = (1<<12); >> +unsigned long loops_per_jiffy = 1000000000 / HZ; >> >> EXPORT_SYMBOL(loops_per_jiffy); > > this is a factor of ~2400 increase - this will take an eternity to boot > on any older CPU. Only any outb_p's used before loops_per_jiffy is calibrated are affected. This pre-calibation thing is what's historically held this change back (it's been discussed dozens of times before). At 4096, not any machine is going to have an appreciable delay before calibration when switching from the outb to 0x80. Rene. -- 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/