From owner-cvs-src@FreeBSD.ORG Tue Dec 14 23:51:00 2004 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6416A16A4CF; Tue, 14 Dec 2004 23:51:00 +0000 (GMT) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.FreeBSD.org (Postfix) with ESMTP id C6CEE43D60; Tue, 14 Dec 2004 23:50:59 +0000 (GMT) (envelope-from scottl@freebsd.org) Received: from [192.168.254.11] (junior-wifi.samsco.home [192.168.254.11]) (authenticated bits=0) by pooker.samsco.org (8.12.11/8.12.10) with ESMTP id iBENrjYG048291; Tue, 14 Dec 2004 16:53:45 -0700 (MST) (envelope-from scottl@freebsd.org) Message-ID: <41BF7C4C.8020500@freebsd.org> Date: Tue, 14 Dec 2004 16:50:36 -0700 From: Scott Long User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.7.2) Gecko/20040929 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Nate Lawson References: <200411300618.iAU6IkQX065609@repoman.freebsd.org> <200412141333.06213.jhb@FreeBSD.org> <41BF48D4.8080305@root.org> <200412141719.10701.jhb@FreeBSD.org> <41BF6F44.2090407@root.org> In-Reply-To: <41BF6F44.2090407@root.org> X-Enigmail-Version: 0.86.1.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, hits=0.0 required=3.8 tests=none autolearn=no version=2.63 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on pooker.samsco.org cc: cvs-src@freebsd.org cc: src-committers@freebsd.org cc: cvs-all@freebsd.org cc: John Baldwin Subject: Re: cvs commit: src/sys/i386/i386 vm_machdep.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Dec 2004 23:51:01 -0000 Nate Lawson wrote: > John Baldwin wrote: > >> On Tuesday 14 December 2004 03:11 pm, Nate Lawson wrote: >> >>> John Baldwin wrote: >>> >>>> On Tuesday 30 November 2004 01:18 am, Nate Lawson wrote: >>>> >>>>> njl 2004-11-30 06:18:46 UTC >>>>> >>>>> FreeBSD src repository >>>>> >>>>> Modified files: >>>>> sys/i386/i386 vm_machdep.c >>>>> Log: >>>>> MFamd64: Remove the cpu_reset_proxy cruft now that we run boot() on >>>>> cpu 0. Also, restructure cpu_reset to be cleaner (no functional >>>>> change.) >>>> >>>> >>>> FYI, this breaks the 'reset' command from ddb if you panic on a cpu >>>> other >>>> than the BSP. boot() isn't the only function that calls >>>> cpu_reset(), so >>>> perhaps this should be reverted (same for amd64) >>> >>> >>> No, I think we should move forward instead of backward. Entering the >>> debugger should happen on the BSP and possibly other cpus need to be >>> stopped by panic(). >> >> >> Erm, well, that's not always easy since sometimes when you panic you >> can't talk to the other CPUs for whatever reason. Putting back the >> proxy reset doesn't hurt for now but does restore functionality in at >> least some cases. I'd rather have that then certain hard panics not >> get into ddb because we couldn't get onto the BSP to run ddb. > > > Perhaps you could give me some pointers on what is counted on to be > working when panic() is called? I can't come up with a situation where > the proxy code couldn't be used upon entry to ddb. If there were any > cases like this, the proxy code wouldn't work for cpu_reset() either. > Also, in such a case, it's hard to see how ddb could be usable since it > tries to stop other processors, which requires similar code to the proxy. > > Or in other words, if you have enough capability to call panic() or > break to ddb, then you have enough resources to do an IPI and get onto > the BSP. > Doing an IPI is useless if interrupts are disabled on the BSP for whatever reason. Now, if you want to send an NMI, that might be interesting. Scott