Comment # 144 on bug 1112824 from Victor Zhestkov

Hi Richard.
It seems nothing has changed with your kernel.
I found that it's quite easy to check if the issue presents on the system. Just
to use geekbench.
The single core score is very dependent on spectre_v2=retpoline option.
Here is the result with spectre_v2=retpoline:
https://browser.geekbench.com/v4/cpu/11952293
And here is the result with default mitigation for my CPU (IBRS):
https://browser.geekbench.com/v4/cpu/11952353

3981 vs 3140 in single core score.
Multicore difference is insignificant.

The behavior with micro lags in GNOME is the same with the default kernel from
Tumbleweed and from your repo. Microlags are present with IBRS only.

On my other system Lenovo T470p i5-7440HQ there is no difference in geekbench
score with IBRS or retpoline options.