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To: Shrikanth Hegde , "Paul E . McKenney" , Tejun Heo Cc: Boqun Feng , LKML , RCU , linuxppc-dev@lists.ozlabs.org, Boqun Feng References: <97a7d011-d573-4754-9e5d-68b562c64089@linux.ibm.com> <688280dc-78a2-4796-9eaf-e1c058836012@linux.ibm.com> <1b89c25b-7c1d-4ed8-adf3-ac504b6f086a@linux.ibm.com> <5ab8d72e-1a93-4d50-b097-0dde35d81f25@linux.ibm.com> Content-Language: en-US From: Samir M In-Reply-To: <5ab8d72e-1a93-4d50-b097-0dde35d81f25@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-GUID: DO7-BjzqUEunGdmkEcoDQXg_RvS7cBmk X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNDMwMDA2MCBTYWx0ZWRfX3swG14qacGKg fsHYoHu5teEk7SIbW5f2Yj096f5mKnYXTHZ6pUUPVkS3Cv2kd11XiojFLKNG4Y5A113J04prn3o 0tx4oTQ1J3V1oMsQyqC+2Eg3R248IB7YCFX0kOsVo37hdK9oOeaSwOSVczusNIXLAwGNhyxK6Cy 4koDhknBYO4Y45I8hTxm/CyWv4wj4XEamD0up9mVg64Zz/cRVkcY5A6SG0ce0VdWWtPTCtVdA5s cl5r92xG2njS3zX6Nag3xSBsE/F1RjMI33Y9pFDVM3EnE02z1ZNOwxCx/LxmUFyeewCd1en7EKL 4BlrZObMVy2JPj/1RvaAVIqY/aENMJ+i7qRwmSs0RMAeWWyR6dw+tTlA26zAkm7VBg7X+6bvPBu n+kxmSXXTbIghH4HrJIt9QCP8NCh+EH8SHPW1o0AO+jcZ9TfBowVbln0LasdKMFE5kgg1aZq2jy +ZTppyQ52cPM9h7l4Cw== X-Authority-Analysis: v=2.4 cv=Kc7idwYD c=1 sm=1 tr=0 ts=69f2f45e cx=c_pps a=3Bg1Hr4SwmMryq2xdFQyZA==:117 a=3Bg1Hr4SwmMryq2xdFQyZA==:17 a=IkcTkHD0fZMA:10 a=A5OVakUREuEA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=uAbxVGIbfxUO_5tXvNgY:22 a=VwQbUJbxAAAA:8 a=qCof3rqyAAAA:8 a=Z_pkc8uJlxWzUkK9FVYA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=sGiMcuukUhmiu4iKGgn_:22 X-Proofpoint-ORIG-GUID: wnEPhCK_syXVt4zTPa6NRYioY_jvigSB X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-04-30_02,2026-04-28_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 phishscore=0 bulkscore=0 adultscore=0 spamscore=0 malwarescore=0 impostorscore=0 priorityscore=1501 lowpriorityscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2604200000 definitions=main-2604300060 On 29/04/26 11:21 pm, Shrikanth Hegde wrote: > Hi Samir. > > On 4/29/26 3:46 PM, Samir M wrote: >> >> Hi Boqun, >> >> Thank you for pointing me to the existing patches. I have tested both >> Paul's patch [1] and TJ's workqueue patch [2] on my PowerPC system >> (80 CPUs), and can confirm that the workqueue lockup issue is not >> observed. >> > > Can you try only paul's patch and confirm if the issue is fixed? > Hi Shrikanth, I have verified Paul’s “alone” patch, and it resolves the issue no workqueue lockups are observed. Regards, Samir. >> Test Environment: >> - System: PowerPC with 80 CPUs ( e.g. PowerPC LPARs with 80 online >> and 384 possible CPUs) >> - Kernel version: Latest upstream (7.1-rc1) >> >> Regression Testing Results: >> All tests completed successfully with no issues observed: >> - Hackbench >> - Kernel selftests >> - LTP scheduler tests >> >> The workqueue lockup that was previously occurring is no longer >> present with the patches applied. >> >> References: >> [1]: https://lore.kernel.org/rcu/ed1fa6cd-7343-4ca3-8b9d- >> d699ca496f83@paulmck-laptop/ >> [2]: https://lore.kernel.org/rcu/adlHKowvhn8AGXCc@slm.duckdns.org/ >> >> Best regards, >> Samir >