Split 7.2 OFH - Cannot push more tasks into the du_cell#0 worker queue with priority=max.

[hudouseko]

Hi all,
I'm trying to bring up srs5G with ORAN 7.2 fronthaul. Signal is on fronthaul DL is OK in terms of content and timing, nevertheless once per second, there is roughly 50ms gap, where nothing is being transmitted in DL on fronthaul. Corresponding entries in the gnb.log are the following:

2023-12-06T10:44:41.978818 [FAPI ] [W] [ 693.6] Real-time failure in FAPI: Received UL_TTI.request message from slot 692.192023-12-06T10:44:41.978836 [FAPI ] [W] [ 693.8] Real-time failure in FAPI: Received late DL_TTI.request from slot 693.0 2023-12-06T10:44:41.978839 [ALL ] [W] Cannot push more tasks into the du_cell#0 worker queue with priority=max. Maximum size is 8 2023-12-06T10:44:41.978840 [MAC ] [W] [ 693.1] Skipped slot indication=693.8. Cause: DL task queue is full. 2023-12-06T10:44:41.978845 [ALL ] [W] Cannot push more tasks into the du_cell#0 worker queue with priority=max. Maximum size is 8 2023-12-06T10:44:41.978845 [MAC ] [W] [ 693.1] Skipped slot indication=693.10. Cause: DL task queue is full. 2023-12-06T10:44:41.978846 [FAPI ] [W] [ 693.10] Real-time failure in FAPI: Received late DL_TTI.request from slot 693.1 2023-12-06T10:44:41.978848 [ALL ] [W] Cannot push more tasks into the du_cell#0 worker queue with priority=max. Maximum size is 8 2023-12-06T10:44:41.978848 [MAC ] [W] [ 693.2] Skipped slot indication=693.11. Cause: DL task queue is full.

Is there something I should focus on/try out in troubleshooting?
I'm running it on 2 CPU server, already pinned vCPUs to one NUMA node. I have utilized https://github.com/srsran/srsRAN_Project/blob/main/scripts/srsran_performance as well to disable frequency scaling as well as other actions covered by the script.

Configuration of the gnb:
gnb_cfg.yml.txt

GNB is running in a VM with dedicated 8x vCPUs (Intel(R) Xeon(R) Gold 6238 CPU @ 2.10GHz) and 16GB RAM

[ismagom]

It seems something is interrupting the CPU every 50 ms and generating those lates. Have you tunned the VM for real-time performance? Can you try to reproduce in bare metal?

What kind of traffic are you doing?

[hudouseko]

Hi, I have tried on host (outside of VM) and that works fine - thanks a lot for the hint. I'll try to tune VM performance and will let you know if I figure out how to get rid of the issue. But anyway even if not, I'm fine running on bare metal as well. So far I was running no traffic - only DL signal on ORAN 7-2 fronthaul.