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Fri, 12 May 2023 00:05:22 GMT Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0BFE52004D; Fri, 12 May 2023 00:05:22 +0000 (GMT) Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B14E120040; Fri, 12 May 2023 00:05:21 +0000 (GMT) Received: from li-ce58cfcc-320b-11b2-a85c-85e19b5285e0 (unknown [9.179.0.234]) by smtpav07.fra02v.mail.ibm.com (Postfix) with SMTP; Fri, 12 May 2023 00:05:21 +0000 (GMT) Date: Fri, 12 May 2023 02:05:19 +0200 From: Halil Pasic To: Markus Armbruster Cc: Cornelia Huck , qemu-devel@nongnu.org, Halil Pasic Subject: Re: css_clear_io_interrupt() error handling Message-ID: <20230512020519.6dab1a81.pasic@linux.ibm.com> In-Reply-To: <87r0rnjbz0.fsf@pond.sub.org> 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> Organization: IBM X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: IF_7C4fGP8DfzbUe_kq44UVG_LuBccNk X-Proofpoint-ORIG-GUID: qm5lkBJIDUPQL4-Q2Qy5zkTIG3sG1CEP X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-05-11_19,2023-05-05_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=725 clxscore=1015 impostorscore=0 suspectscore=0 malwarescore=0 mlxscore=0 adultscore=0 spamscore=0 lowpriorityscore=0 priorityscore=1501 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2304280000 definitions=main-2305110205 Received-SPF: pass client-ip=148.163.158.5; envelope-from=pasic@linux.ibm.com; helo=mx0b-001b2d01.pphosted.com X-Spam_score_int: -19 X-Spam_score: -2.0 X-Spam_bar: -- X-Spam_report: (-2.0 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_MSPIKE_H2=-0.001, 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 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. > > > [*] 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? Regards, Halil