Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261943AbVEWUUN (ORCPT ); Mon, 23 May 2005 16:20:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261942AbVEWUUN (ORCPT ); Mon, 23 May 2005 16:20:13 -0400 Received: from prgy-npn1.prodigy.com ([207.115.54.37]:39101 "EHLO oddball.prodigy.com") by vger.kernel.org with ESMTP id S261943AbVEWUUG (ORCPT ); Mon, 23 May 2005 16:20:06 -0400 Message-ID: <42923B19.7070306@tmr.com> Date: Mon, 23 May 2005 16:20:41 -0400 From: Bill Davidsen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.6) Gecko/20050319 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Russell King CC: Andi Kleen , Dave Jones , akpm@osdl.org, linux-kernel@vger.kernel.org Subject: Re: tickle nmi watchdog whilst doing serial writes. References: <20050513184806.GA24166@redhat.com> <20050515130742.A29619@flint.arm.linux.org.uk> <428BDCAD.2090307@mvista.com> <20050519083338.A28946@flint.arm.linux.org.uk> In-Reply-To: <20050519083338.A28946@flint.arm.linux.org.uk> 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 Content-Length: 1397 Lines: 31 Russell King wrote: > On Wed, May 18, 2005 at 05:24:13PM -0700, George Anzinger wrote: > >>Um... I would think the real fix is to set the UART up to generate the modem >>status interrupt and eliminate the pole loop. Why can't this be done? I, for >>one, don't want my cpu looping in the serial driver, even more so with the >>interrupt system off. This, in my mind, is a real bug in the serial driver and >>should be so handled. > > > Because printk is *synchronous*. It never returns until it's written > the entire message. There is no buffering. > > Extra complexity, adding reliance on interrupts, etc all means that > you reduce the probability that you'll get the panic or oops message > out of the system. > This is a fine reason to loop in the serial code, I guess, but what's the reason for allowing the NMI oops? Having use of the serial console to catch an oops actually CAUSE an oops doesn't seem desirable, and is probably more likely than a hardlock in the serial driver. -- -bill davidsen (davidsen@tmr.com) "The secret to procrastination is to put things off until the last possible moment - but no longer" -me - 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/