Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262447AbVEMXYn (ORCPT ); Fri, 13 May 2005 19:24:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262622AbVEMXWl (ORCPT ); Fri, 13 May 2005 19:22:41 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:34251 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S262624AbVEMXVJ (ORCPT ); Fri, 13 May 2005 19:21:09 -0400 Date: Sat, 14 May 2005 01:21:22 +0200 From: Pavel Machek To: Lee Revell Cc: Andi Kleen , Alexander Nyberg , Jan Beulich , discuss@x86-64.org, linux-kernel@vger.kernel.org Subject: Re: [discuss] Re: [PATCH] adjust x86-64 watchdog tick calculation Message-ID: <20050513232122.GD2016@elf.ucw.cz> References: <1115892008.918.7.camel@localhost.localdomain> <20050512142920.GA7079@openzaurus.ucw.cz> <20050513113023.GD15755@wotan.suse.de> <20050513195215.GC3135@elf.ucw.cz> <1116019676.6380.37.camel@mindpipe> <20050513225127.GB2016@elf.ucw.cz> <1116024993.6380.47.camel@mindpipe> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1116024993.6380.47.camel@mindpipe> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1436 Lines: 37 Hi! > > > > > > Because it kills machine when interrupt latency gets too high? > > > > > > Like reading battery status using i2c... > > > > > > > > > > That's a bug in the I2C reader then. Don't shot the messenger for bad news. > > > > > > > > Disagreed. > > > > > > > > Linux is not real time OS. Perhaps some real-time constraints "may not > > > > spend > 100msec with interrupts disabled" would be healthy > > > ^^^^ > > > You mean "microseconds", right? 100ms will be perceived by the user as, > > > well, their machine freezing for 100ms... > > > > I did mean miliseconds. IIRC current watchdog is at one second and it > > still triggers even in cases when operation just takes too long. > > I thought there was an understanding that 1 ms would be the target for > desktop responsiveness. So yes, disabling interrupts for more than 1ms > is considered a bug. I do not think so. In may be "worth fixing", but no, that does not mean you should stick "if ints_disabled > 1msec panic()" into code. That would make most systems unusable. Think pio-only disks, for example. Think serial console. Pavel -- Boycott Kodak -- for their patent abuse against Java. - 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/