Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 27 Aug 2002 15:51:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 27 Aug 2002 15:51:53 -0400 Received: from hq.fsmlabs.com ([209.155.42.197]:42138 "EHLO hq.fsmlabs.com") by vger.kernel.org with ESMTP id ; Tue, 27 Aug 2002 15:51:52 -0400 Date: Tue, 27 Aug 2002 13:54:01 -0600 From: yodaiken@fsmlabs.com To: "Richard B. Johnson" Cc: Mark Hounschell , "Wessler, Siegfried" , "'linux-kernel@vger.kernel.org'" Subject: Re: interrupt latency Message-ID: <20020827135400.A31990@hq.fsmlabs.com> References: <3D6BB9E2.DE71FE2C@compro.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: ; from root@chaos.analogic.com on Tue, Aug 27, 2002 at 02:01:43PM -0400 Organization: FSM Labs Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1020 Lines: 23 On Tue, Aug 27, 2002 at 02:01:43PM -0400, Richard B. Johnson wrote: > This cannot be. A stock kernel-2.4.18, running a 133 MHz AMD-SC520, > (like a i586) with a 33 MHz bus, handles interrupts off IRQ7 (the lowest > priority), from the 'printer port' at well over 75,000 per second without > skipping a beat or missing an edge. This means that latency is at least > as good as 1/57,000 sec = 0.013 microseconds. Assuming you mean 75,000 then ... Thats 0.013 MILLISECONDS which is 13 microseconds and its not likely. I bet that your data source drops data or looks at some handshake pins on the parallel connect. -- --------------------------------------------------------- Victor Yodaiken Finite State Machine Labs: The RTLinux Company. www.fsmlabs.com www.rtlinux.com - 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/