Received: by 2002:a25:824b:0:0:0:0:0 with SMTP id d11csp967383ybn; Wed, 2 Oct 2019 08:53:17 -0700 (PDT) X-Google-Smtp-Source: APXvYqzg1RzZEIi3j44cwb2VcRdrCqdPSDehuu1gkippQfgDBDnDct22qu3T8L21z1wN184wVzFM X-Received: by 2002:a05:6402:1a4c:: with SMTP id bf12mr4539189edb.277.1570031597118; Wed, 02 Oct 2019 08:53:17 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1570031597; cv=none; d=google.com; s=arc-20160816; b=I+c9boXxlKspnPI9eHNsW6hpe2aiKtMbE/uu/PSYaa4+a0ZqoklV1T8CYy320rhnvB p5x0Z5jOxJH5h17XB0TK0gGpdLbc75v29RAU+MRZ2D5oAvdc/eXDZirZF7eRHX1rqH8v SaS5xdhxguWccl96cJ0pj0FVbaiYk83O8DuD0DJiqqHdhYBfNjGKJUyuDoqtrflI5PAR EIF6XHD8dQnITjU1cqgGO6ADmByp8jLpnifzfzg6dSEMTzaUY1lF7AM0pIyLooA7/7Kb hBe8YrJcCOzD840tp8NX7K5Lq6pzrwvW6ZBDd8lFaivQN8lEppu37VBFZoOH8QPr2Dq7 z+gg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject; bh=O49tIFb5BZ39GF8WyTaHBNy5UIOGc/fsTovFjtQIQEs=; b=NpMSD7HPy7rDWjhDjgI1Opz5Ke5Mu2wcVkiRnY+P+D6Z19cL6PhlvYUf6+l1OTwP3T neyIUDoBMvMzWm8jXcH4ohUvkMt4s47MNMkbd7Ao6mWnXlHyQK7LG5+9GYg5s6rph6eE w+pRRQ4bTkVWvBUW0dXPmYj2PwZXrkH3zUZkBZGlHcp0J7Gw5dP42G1u1PcI+Pk+GvPU iixOAl2VL4taMoRcid+m9qL5RVSiQ78Nc7ZCz1Rs60VN1S771gcm5REIE8ywijsdZEX7 CxAOzesD/UUv24iyjIZtaQzTZbBfHcA9gKGs+6stQkdHm7+39b0MieuC5Ia2RHN9/fw2 qkCQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id f57si12029724ede.78.2019.10.02.08.52.52; Wed, 02 Oct 2019 08:53:17 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727653AbfJBO7L (ORCPT + 99 others); Wed, 2 Oct 2019 10:59:11 -0400 Received: from mx2.suse.de ([195.135.220.15]:45962 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726070AbfJBO7L (ORCPT ); Wed, 2 Oct 2019 10:59:11 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id C15BCABD3; Wed, 2 Oct 2019 14:59:09 +0000 (UTC) Subject: Re: [Xen-devel] [PATCH] x86/xen: Return from panic notifier To: Boris Ostrovsky Cc: james@dingwall.me.uk, xen-devel@lists.xenproject.org, Juergen Gross , linux-kernel@vger.kernel.org References: <20191001151633.1659-1-boris.ostrovsky@oracle.com> <9b3f955c-ad76-601f-2b58-fa9dc4608c72@suse.com> <924f41b2-7779-9c56-9b71-56523756ecdc@oracle.com> <5650904d-b616-5ee7-216a-a0ac28d7426d@suse.com> <9d6b6b00-a3b1-95b4-7633-597c0094ab90@oracle.com> From: Jan Beulich Message-ID: <63155d02-1082-3f26-6c2f-76aa3b753302@suse.com> Date: Wed, 2 Oct 2019 16:59:16 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <9d6b6b00-a3b1-95b4-7633-597c0094ab90@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02.10.2019 16:14, Boris Ostrovsky wrote: > On 10/2/19 9:42 AM, Jan Beulich wrote: >> >> I can only guess that the thinking probably was that e.g. external >> dumping (by the tool stack) would be more reliable (including but >> not limited to this meaning less change of state from when the >> original crash reason was detected) than having the domain dump >> itself. > > > We could register an external dumper (controlled by a boot option > perhaps, off by default) that will call directly into hypervisor with > SHUTDOWN_crash. That will guarantee that we will complete the notifier > chain without relying on priorities. (Of course this still won't address > a possible new feature in panic() that might be called post-dumping) > > If you think it's worth doing this can be easily added. Well, I think this is the better option than potentially pingponging between the two extremes, because one wants it the way it currently is and another wants it the way this patch changes things to. Jan