Not sure the status of this bug, but I just installed Ubuntu 5.4.0-6ubuntu1~16.04.2 with Linux version 4.4.0-38-generic on a dual core machine with an onboard GeForce 9400.
I ran into the issue of one of the cores running at 100% when ever I turned on my monitor and connected to the terminal via DVI/HDMI. If I reboot and only ssh to the machine I get <1% usage across both cores at idle, but as soon as I switch on the monitor one of the cores jumps to 100% I ran "sudo perf record -g -a sleep 20" then "sudo perf report --sort comm,dso" and this is what I found in the report: - 100.00% 99.85% kworker/1:7 [kernel.kallsyms] - 100.00% ret_from_fork kthread worker_thread - process_one_work - 99.97% nvif_notify_work + nouveau_connector_hotplug + 0.03% nvkm_notify_work + 0.00% vmstat_update 0.00% native_write_msr_safe - 100.00% 0.09% kworker/1:7 [nouveau] - 99.88% nvif_notify_work - nouveau_connector_hotplug - 99.87% drm_helper_hpd_irq_event - 99.86% nouveau_connector_detect + 96.48% drm_get_edid + 3.39% i2c_transfer + 0.00% drm_mode_object_find + 0.00% mutex_unlock + 0.01% mutex_lock + 0.09% ret_from_fork + 0.03% nvkm_notify_work + 99.96% 0.00% kworker/1:7 [drm_kms_helper] + 99.93% 0.05% kworker/1:7 [i2c_algo_bit] + 96.56% 0.01% kworker/1:7 [drm] + 0.01% 0.00% kworker/1:7 [forcedeth] So it looks like I got struck but this same hotplug issue. If I connect to my monitor via VGA i don't get the CPU spike...works for me since I am running my machine headless but if anyone else needs to connect via HDMI/DVI this could be an issue. I'm not sure if installing the nvidia drivers fixes the hotplug cpu spike up. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-nouveau in Ubuntu. https://bugs.launchpad.net/bugs/1248256 Title: [MacBookPro10,1] Plugging in displayport monitor causes kworker to take 100% CPU To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1248256/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp