X slow rendering performance with i915 driver
Submitted by Dzianis Bazhok
Assigned to Xorg Project Team
Created attachment 142426 X process perf flamegraph
I've noticed that after reboot there is a high cpu usage and slow rendering performance. Using top I've found that X process uses 10-15% CPU. intel_gpu_top shows 90-100% GPU usage but on screen nothing happens. After 10-15 minutes this load may disappear and performance returns to normal.
I'm using Dell XPS 13 with integrated Intel HD Graphics 620. Software versions: kernel: 4.19.0-gentoo xorg-server: 1.20.3 xorg-proto: 2018.4 kde plasma: 5.51.0 kde plasma-desktop: 5.14.3
In attachments I'll provide reports of perf tool for X process and i915 events.