From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261733AbVGOBNL (ORCPT ); Thu, 14 Jul 2005 21:13:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261737AbVGOBNL (ORCPT ); Thu, 14 Jul 2005 21:13:11 -0400 Received: from mail.tmr.com ([64.65.253.246]:29625 "EHLO gaimboi.tmr.com") by vger.kernel.org with ESMTP id S261733AbVGOBNK (ORCPT ); Thu, 14 Jul 2005 21:13:10 -0400 Message-ID: <42D70F2C.4020706@tmr.com> Date: Thu, 14 Jul 2005 21:19:40 -0400 From: Bill Davidsen Organization: TMR Associates Inc, Schenectady NY User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7) Gecko/20040616 X-Accept-Language: en-us, en MIME-Version: 1.0 To: David Lang CC: Vojtech Pavlik , Con Kolivas , linux-kernel@vger.kernel.org, "Martin J. Bligh" , Lee Revell , Diego Calleja , azarah@nosferatu.za.org, akpm@osdl.org, cw@f00f.org, torvalds@osdl.org, christoph@lameter.org Subject: Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt References: <200506231828.j5NISlCe020350@hera.kernel.org> <20050712121008.GA7804@ucw.cz> <200507122239.03559.kernel@kolivas.org> <200507122253.03212.kernel@kolivas.org> <42D3E852.5060704@mvista.com> <20050712162740.GA8938@ucw.cz> <42D540C2.9060201@tmr.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org David Lang wrote: > On Wed, 13 Jul 2005, Bill Davidsen wrote: > >> How serious is the 1/HZ = sane problem, and more to the point how >> many programs get the HZ value with a system call as opposed to >> including a header or building it in? I know some of my older >> programs use header files, that was part of the planning for the >> future even before 2.5 started. At the time I didn't expect to have >> to use the system call. > > > in binary 1/100 or 1/1000 are not sane values to start with so I don't > think that that this is likly to be that critical (remembering that > the kernel doesn't do floating point math) The kernel isn't the issue, it's programs which do timing and get values in ticks which they convert to time by dividing by HZ. I at least get that from a header, proper way would be with the syscall. -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979