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Mon, 29 Jul 2024 11:39:15 GMT Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C2B7E2004D; Mon, 29 Jul 2024 11:39:13 +0000 (GMT) Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 775F52004F; Mon, 29 Jul 2024 11:39:13 +0000 (GMT) Received: from li-1de7cd4c-3205-11b2-a85c-d27f97db1fe1.ibm.com (unknown [9.171.16.76]) by smtpav07.fra02v.mail.ibm.com (Postfix) with ESMTPS; Mon, 29 Jul 2024 11:39:13 +0000 (GMT) From: "Marc Hartmayer" To: Lai Jiangshan , linux-kernel@vger.kernel.org Cc: Lai Jiangshan , Tejun Heo Subject: Re: [PATCH] workqueue: Remove incorrect "WARN_ON_ONCE(!list_empty(&worker->entry));" from dying worker In-Reply-To: <20240725010437.694727-1-jiangshanlai@gmail.com> References: <20240725010437.694727-1-jiangshanlai@gmail.com> Date: Mon, 29 Jul 2024 13:39:12 +0200 Message-ID: <87wml4s9zz.fsf@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: ipS9a1dL7SXRKEXkK3vLD9H-_CqMOvP9 X-Proofpoint-GUID: ofIxgT0QXnOTnNfPLxHyVnvtieggilRb X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16 definitions=2024-07-29_09,2024-07-26_01,2024-05-17_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 bulkscore=0 phishscore=0 adultscore=0 spamscore=0 mlxlogscore=999 suspectscore=0 priorityscore=1501 mlxscore=0 malwarescore=0 clxscore=1015 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2407110000 definitions=main-2407290077 On Thu, Jul 25, 2024 at 09:04 AM +0800, Lai Jiangshan wrote: > From: Lai Jiangshan > > The commit 68f83057b913 ("workqueue: Reap workers via kthread_stop() > and remove detach_completion") changes the procedure of destroying > workers; the dying workers are kept in the cull_list in wake_dying_worker= s() > with the pool lock held and removed from the cull_list by the newly > added reap_dying_workers() without the pool lock. > > This can cause a warning if the dying worker is wokenup earlier than > reaped as reported by Marc: > [=E2=80=A6snip] The crash I reported is fixed by this patch. But I can't say whether the removal of the warning is OK. -- Kind regards / Beste Gr=C3=BC=C3=9Fe Marc Hartmayer IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Wolfgang Wendt Gesch=C3=A4ftsf=C3=BChrung: David Faller Sitz der Gesellschaft: B=C3=B6blingen Registergericht: Amtsgericht Stuttgart, HRB 243294