From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3vSM9r0FmhzDqBV for ; Wed, 22 Feb 2017 00:42:07 +1100 (AEDT) Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v1LDXcMn075062 for ; Tue, 21 Feb 2017 08:42:06 -0500 Received: from e24smtp03.br.ibm.com (e24smtp03.br.ibm.com [32.104.18.24]) by mx0a-001b2d01.pphosted.com with ESMTP id 28r120ud3c-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 21 Feb 2017 08:42:05 -0500 Received: from localhost by e24smtp03.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 21 Feb 2017 10:42:03 -0300 Received: from d24relay02.br.ibm.com (d24relay02.br.ibm.com [9.18.232.42]) by d24dlp02.br.ibm.com (Postfix) with ESMTP id CE8521DC006D for ; Tue, 21 Feb 2017 08:42:01 -0500 (EST) Received: from d24av05.br.ibm.com (d24av05.br.ibm.com [9.18.232.44]) by d24relay02.br.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v1LDfqT232374890 for ; Tue, 21 Feb 2017 10:42:00 -0300 Received: from d24av05.br.ibm.com (localhost [127.0.0.1]) by d24av05.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v1LDfSjo027931 for ; Tue, 21 Feb 2017 10:41:29 -0300 Subject: Re: [PATCH 2/3] powerpc/xmon: drop the nobt option from xmon plus minor fixes To: Michael Ellerman , linuxppc-dev@lists.ozlabs.org References: <1487290677-7200-1-git-send-email-gpiccoli@linux.vnet.ibm.com> <1487290677-7200-3-git-send-email-gpiccoli@linux.vnet.ibm.com> <87poicm8cw.fsf@concordia.ellerman.id.au> Cc: paulus@samba.org, npiggin@gmail.com, xinhui.pan@linux.vnet.ibm.com From: "Guilherme G. Piccoli" Date: Tue, 21 Feb 2017 10:41:03 -0300 MIME-Version: 1.0 In-Reply-To: <87poicm8cw.fsf@concordia.ellerman.id.au> Content-Type: text/plain; charset=windows-1252 Message-Id: <6d952aa0-fb14-adf0-de3f-16770a50dd6f@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 02/21/2017 02:16 AM, Michael Ellerman wrote: > "Guilherme G. Piccoli" writes: >> Subject: Re: [PATCH 2/3] powerpc/xmon: drop the nobt option from xmon plus minor fixes > > In future please use the same version number for all patches of a > series. > > ie. This should include a v2, like the rest of the patches in the series. > > It confuses the tools to have "v2 1/3" "2/3" "v2 3/3". > > I realise that might seem a little odd when a patch is new to the > series, but the version is the version *of the series*, not the > individual patches. > > For a new patch you can just add after the change log: > > --- > v2: New for v2 of the series. > > > For example. Sure, thanks for the hint and for explain very well how I should proceed! Unfortunately...as you probably already noticed, I'm only seeing this after sent the v2 of the series heheh Sorry, next time I'll follow your suggestion (TBH I thought of it before sending this, but I got more inclined in mess with the series numbering heheh) > >> The xmon parameter nobt was added long time ago, by commit 26c8af5f01df >> ("[POWERPC] print backtrace when entering xmon"). The problem that time >> was that during a crash in a machine with USB keyboard, xmon wouldn't >> respond to commands from the keyboard, so printing the backtrace wouldn't >> be possible. >> >> Idea then was to show automatically the backtrace on xmon crash for the >> first time it's invoked (if it recovers, next time xmon won't show >> backtrace automatically). The nobt parameter was added _only_ to prevent >> this automatic trace show. Seems long time ago USB keyboards didn't work >> that well! >> >> We don't need it anymore, but the feature of auto showing the backtrace >> on first crash seems interesting (imagine a case of auto-reboot script), >> so this patch keeps the functionality, yet removes the nobt parameter. > > > I'm going to take this as-is, because I want to get it in for v4.11. > > But I don't think we need the auto back trace logic at all. If anything > it's an anti-feature IMHO. > > Imagine you're debugging a machine and you drop into xmon to check > something, then drop out again. > > Then you go away and leave the box, and it crashes into xmon, but xmon > doesn't print a backtrace because you've already been in xmon. Usually > you can just get on the console and hit 't', but sometimes the machine > crashes so hard that xmon doesn't take input - in which case you now > have no backtrace. :sadface: > > So I'll send a follow-up patch to remove the auto backtrace stuff > completely and see if anyone objects. > OK, guess you noticed in your next message I kept the trace behavior...let's discuss there =) Cheers, Guilherme > cheers >