Dell XPS 7390 Intel Ice Lake Performance Hit Hard By A Linux Kernel Regression

[kcrudup]

Could you please send this output to check if power limits got messed up:

grep . /sys/class/powercap/intel-rapl-mmio/intel-rapl-mmio\:0/*

It's funny you mention RAPL- Michael - there was a BIOS update for the 7390 2-in-1 that among other things, fixed a bug where one of the RAPL registers wouldn't come back after a reboot. Can you see if there was a BIOS update for your 7390?

[speculatrix]

at work I'm running a Dell Inspiron 7370 on Fedora 31. It doesn't run linux too well, as in suspend/resume or hibernate don't work. Also, the laptop has nowhere near enough cooling for the core-i7 processor. Anyway, I digress.

with kernel 5.4 it was fine. not long after upgrading to kernel 5.5 it started locking up, usually when idle, e.g. if I went to lunch, or if I left it running in the evenings, and required a forced power cycle.

[vasu_1970]

This is root caused to wrong power settings.

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1874933

[a7v-user]

Update: User error on my part. Had compositing enabled in my window manager.
Disabled that and got +10% increase instead of a -25% Unigine score.
I don't remember the performance hit being this bad before especially with full-screen applications.

Nothing to do with broken power savings or buggy acpi implementations.
(

I just realized that my Phenom II/Gtx 1660 lost about 30% performance (Unity Valley) since September.
Something ain't right here

. )