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Wythe" , wenjia@linux.ibm.com, wintera@linux.ibm.com, dust.li@linux.alibaba.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org, leonro@nvidia.com, pabeni@redhat.com, edumazet@google.com, sidraya@linux.ibm.com, jaka@linux.ibm.com, oliver.yang@linux.alibaba.com References: <20260806064252.39180-1-alibuda@linux.alibaba.com> <20260806064252.39180-3-alibuda@linux.alibaba.com> Content-Language: en-US From: Mahanta Jambigi In-Reply-To: <20260806064252.39180-3-alibuda@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-ORIG-GUID: 5Z1A-X9Ul4AbIGvY6DC94YAoYjzATQny X-Authority-Analysis: v=2.4 cv=e5k2j6p/ c=1 sm=1 tr=0 ts=6a7570fd cx=c_pps a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17 a=IkcTkHD0fZMA:10 a=Sv0fKeRqtYgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=Y2IxJ9c9Rs8Kov3niI8_:22 a=V8dVQpNtD287ao_dHYcA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-GUID: wg8Cl8HsGDvmhnxFt346RO9uKVX49UbI X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODA3MDAzNiBTYWx0ZWRfX8hvqpcHirg8N rDGFekFISNfXNrpmQMugTeNqOkDZXV/ih3Ew6h8biHE+N2VJrqP7Gqw/Zo+vsGRA4wPRjVIg+OI tlcAxwWGQB86l5GnQIPyPXWAyR11S2vBO+8GRFM9puNRNe769AEMq5f43gkyfG+YxNOruHs4xXI fIgLtK2zFNpuxjxmFMJ5UpW8LWC2K48ZIpe38vdAqDuc1jSjDRwig/imJ1oIHOuDn7RT36VQ9EB Vr/SnhKzEoDnWVlM/SAxd3ptYXrZqdfHrE87byfW5l/iKIhSzO5cKdjKBmaPrA8chZhi/3HZOxM eVcXo+ql2P9K2ommoip7lkVQsYcNNkF2EKBPm+Hf7Lzeax8L2sukCFWl6h1Gkf+fjQPEOaMw/Sh CDGDYr42woHwEdmq9kVavdBNjpSavmhR8uLy5OkqyPdKUGFaeKhSgWNNMiTn7gAEY/78zSHbKSa QOK+I2G/Z6KmCEY39mg== X-Proofpoint-Spam-Info: AW1haW4tMjYwODA3MDAzNiBTYWx0ZWRfX+EzpRCfcR/D3 z5rur2urkutzrnix7KXx9vDh9L8Hw9fSoYt7wYtB9PkhIgI82HQuzTJYUHu/giKMYbDkKJd3Yb3 FEgvMVCT/r7dXRZXkB1cjSbN0O6U1Vc= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-07_01,2026-08-06_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 impostorscore=0 priorityscore=1501 adultscore=0 phishscore=0 clxscore=1015 malwarescore=0 spamscore=0 lowpriorityscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608070036 On 06/08/26 12:12 pm, D. Wythe wrote: > smc_wr_tx_get_free_slot() waits for a free TX slot with > wait_event_interruptible_timeout(). Since the wait_event family > enqueues waiters as non-exclusive, wake_up() may wake multiple > waiters even though only one can use the slot, causing > thundering-herd contention when slots are scarce. Have you run any performance benchmarks (e.g. redis-benchmark or uperf) to quantify the benefit of this change? Since the motivation is to reduce contention caused by multiple waiters being awakened for a single available TX slot, it would be helpful to see measurable results. Please share the baseline and patched throughput figures, and any observed throughput differences.