Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 11 Jul 2002 17:05:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 11 Jul 2002 17:05:12 -0400 Received: from freesurfmta01.sunrise.ch ([194.230.0.16]:60140 "EHLO freesurfmail.sunrise.ch") by vger.kernel.org with ESMTP id ; Thu, 11 Jul 2002 17:05:08 -0400 Message-ID: <3D298E8200068368@freesurfmta01.sunrise.ch> (added by postmaster@freesurf.ch) From: "Per Jessen" To: "linux-kernel@vger.kernel.org" Date: Thu, 11 Jul 2002 23:28:31 +0200 Reply-To: "Per Jessen" X-Mailer: PMMail 98 Professional (2.01.1600) For Windows 95 (4.0.1212) MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Subject: Re: Periodic clock tick considered harmful (was: Re: HZ, preferably as small as possible) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1552 Lines: 41 On Thu, 11 Jul 2002 09:44:35 -0700, dank@kegel.com wrote: >Mark Mielke wrote: >> >> On Wed, Jul 10, 2002 at 04:09:21PM -0600, Cort Dougan wrote: >> > Yes, please do make it a config option. 10x interrupt overhead makes me >> > worry. It lets users tailor the kernel to their expected load. >> >> All this talk is getting to me. >> >> I thought we recently (1 month ago? 2 months ago?) concluded that >> increases in interrupt frequency only affects performance by a very >> small amount, but generates an increase in responsiveness. The only >> real argument against that I have seen, is the 'power conservation' >> argument. The idea was, that the scheduler itself did not execute >> on most interrupts. The clock is updated, and that is about all. > >On UML and mainframe Linux, *any* periodic clock tick >is heavy overhead when you have a large number of >(mostly idle) instances of Linux running, isn't it? Without knowing what UML is in this context, but assuming that mainframe means IBM s390 mainframes, I can confirm that any periodic clock tick is heavy overhead. With or without (mostly) idle instances. /Per regards, Per Jessen, Zurich http://www.enidan.com - home of the J1 serial console. Windows 2001: "I'm sorry Dave ... I'm afraid I can't do that." - 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/