Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764622AbXJOWXj (ORCPT ); Mon, 15 Oct 2007 18:23:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754385AbXJOWXa (ORCPT ); Mon, 15 Oct 2007 18:23:30 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:39570 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751330AbXJOWX3 (ORCPT ); Mon, 15 Oct 2007 18:23:29 -0400 Date: Tue, 16 Oct 2007 00:23:06 +0200 From: Ingo Molnar To: Linus Torvalds Cc: Boaz Harrosh , Jeff Garzik , linux-kernel@vger.kernel.org, James Bottomley Subject: Re: [patch] scsi: fix crash in gdth_timeout() Message-ID: <20071015222306.GA19773@elte.hu> References: <20071015165534.GA17833@elte.hu> <4713A9FA.4050209@garzik.org> <4713B4E7.2050001@panasas.com> <20071015192703.GA7279@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.14 (2007-02-12) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7-deb -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2033 Lines: 43 * Linus Torvalds wrote: > On Mon, 15 Oct 2007, Ingo Molnar wrote: > > > > heh. Incidentally i was thinking about using KVM for automated > > testing. > > Using emulators to test device drivers is almost certain to be > pointless. something like that wont enable 100% coverage (or even reasonable coverage for most hardware), so it's no replacement for actual hard testing, but it could push out the domain of minimally tested code quite a bit and increase the quality of the kernel. Races are always tough and so are bugs on the side of the hardware, but it's the silly boot-time crash showstoppers and "device does not work anymore" mistakes that causes us to lose most of the testers and early adopters. I'm not really worried about the 1% of bugs that are tough to find and fix (because they are actually fun to find and fix), i'm worried about the 99% easy and boring bugs - because they annoy users just as much as the exciting bugs do. If we fix them faster then there's more time (and more tester stamina) left for the harder to find bugs. so i think adding redundancy in form of a simplified hw emulator can certainly not hurt and fundamentally increases robustness - and it will definitely reduce the chance for a whole host of stupid bugs that are not in the hardware but are in the ~4 million lines of Linux driver codebase. Limits and scalability would also be testable: "if i put 32 of these networking cards into a Linux box, will the Linux driver blow up". not that i think this is realistic for any significant portion of the hardware currently - unless some hw maker starts doing it. But KVM will have a good portion of the core PC platform emulated (APIC, etc.) - and that's a nice step forward already. Ingo - 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/