Re: Bug#855183: linux-image-4.9.0-0.bpo.1-amd64: modprobe intel_rapl_perf stay in uninterruptible sleep

From: Miloslav HÅla
Date: Tue Feb 21 2017 - 04:11:01 EST

Dne 21.02.2017 v 0:24 Thomas Gleixner napsal(a):
On Mon, 20 Feb 2017, Miloslav HÅla wrote:
Dne 17.02.2017 v 11:47 Thomas Gleixner napsal(a):
What's really confusing is this information from the bug report:

" When I changed:

Power technology:
- from Energy Efficient
- to Custom

Energy Performance BIAS Setting:
- from Balanced Performance
- to Performance

problem disappeared. systemd-udevd starts normally, module can be
normally rmmod/insmod'ed now, load is 0.07."

Miloslav: Is there any chance you can try a 4.10-rc8 kernel on that

I compiled 4.10-rc8 kernel with a stock '/boot/config-4.9.0-0.bpo.1-amd64'
config from Debian Jessie backports. Then I reverted BIOS settings to previous
state and rebooted the server. Kernel and all modules loaded normally,
rmmod/insmod intel_rapl_perf passed normally.

Then, without any BIOS change, I rebooted with stock 4.9.0-0.bpo.1-amd64 and
suprisingly, everything works, I cannot reproduce it.

My knowledge on the field of BIOS are shallow. I don't know what I can do to
reproduce the bug now.

Did you just reboot or go through a cold start? That might make a difference.

Reboot only. I'll test it again in next maintenance window.

Regards, Milo