From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 83184C77B7D for ; Mon, 15 May 2023 06:40:07 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pyRrp-0005tD-0k; Mon, 15 May 2023 02:39:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pyRrn-0005t0-Uk for qemu-devel@nongnu.org; Mon, 15 May 2023 02:39:31 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pyRrm-0004XL-AB for qemu-devel@nongnu.org; Mon, 15 May 2023 02:39:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684132768; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=msUFI9qm2KBlodzGejFVmSv3jyIdrBbWGzNG92u0N60=; b=M2MTCvZPre1dyJ6t6yWZ8KhnCgkuiAsGz3ksEICYtx9dEdsbgmGczRHJ4imJqB7AvkvYvz Pk6QqVfa8g9RW5D1iyZRMDaE9eyFca2DwFCxxR4lKXXjckhW79igvDIVCwUvm7yvaIvvS1 ijcMthGULDmW8wPX5h7j/nm2cSzOUgs= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-115-c5sfBvHPMU-TM2GCXaZ5SQ-1; Mon, 15 May 2023 02:39:25 -0400 X-MC-Unique: c5sfBvHPMU-TM2GCXaZ5SQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6E402384952A; Mon, 15 May 2023 06:39:25 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.91]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4D25B63F5F; Mon, 15 May 2023 06:39:25 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 27DB021E6806; Mon, 15 May 2023 08:39:24 +0200 (CEST) From: Markus Armbruster To: Halil Pasic Cc: Cornelia Huck , qemu-devel@nongnu.org Subject: Re: css_clear_io_interrupt() error handling References: <87fs87ny6e.fsf@pond.sub.org> <873547dwn0.fsf@redhat.com> <20230509193637.678780aa.pasic@linux.ibm.com> <874jokae8j.fsf@pond.sub.org> <20230511034355.0b916dcb.pasic@linux.ibm.com> <87r0rnjbz0.fsf@pond.sub.org> <20230512020519.6dab1a81.pasic@linux.ibm.com> Date: Mon, 15 May 2023 08:39:24 +0200 In-Reply-To: <20230512020519.6dab1a81.pasic@linux.ibm.com> (Halil Pasic's message of "Fri, 12 May 2023 02:05:19 +0200") Message-ID: <87ttwecd43.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Halil Pasic writes: > On Thu, 11 May 2023 14:20:51 +0200 > Markus Armbruster wrote: > [..] >> > >> > In my opinion the best way to deal with such situations would be to >> > abort() in test/development and log a warning in production. Of course >> >> Understand, but... >> >> > assert() wouldn't give me that, and it wouldn't be locally consistent at >> > all. >> >> ... nothing behaves like that so far. >> > > I understand. And I agree with all statements from your previous mail. > >> Let's try to come to a conclusion. We can either keep the current >> behavior, i.e. abort(). Or we change it to just print something. >> >> If we want the latter: fprintf() to stderr, warn_report(), or trace >> point? >> >> You are the maintainer, so the decision is yours. >> >> I could stick a patch into a series of error-related cleanup patches I'm >> working on. > > I would gladly take that offer. Given that we didn't see any crashes and > thus violations of assumptions up till now, and that both the kvm and the > qemu implementations are from my perspective stable, I think not forcing > a crash is a good option. From the options you offered, warn_report() > looks the most compelling to me, but I would trust your expertise to pick > the actually best one. > > Thank you very much. You're welcome! >> [*] I'm rather fond of the trick to have oopsie() fork & crash. > > I never thought of this, but I do actually find it very compelling > to get a dump while keeping the workload alive. Especially if > it was oopsie_once() so one does not get buried in dumps. But we don't > do things like this in QEMU, or do we? No, we don't.