Linux 4.8 Bringing ACPI Low-Power Idle, Intel Denverton Support

[nkalkhof]

That's why I mentioned it. BFQ is an out-of-tree I/O Scheduler. But you should stick with CFQ. That shouldn't have any different results.

Ok just gave your configuration a try. It took some time to build . no changes in pc states however. bummer. also tested current drm-intel git with same results. is probably the hardware configuration. I have a Lenovo T440p, I7-4600M. My old Laptop (Lenovo T420, i7 SNB) stays at pc7 ~ 98% when idle.

[RickXy]

Ok just gave your configuration a try. It took some time to build . no changes in pc states however. bummer. also tested current drm-intel git with same results. is probably the hardware configuration. I have a Lenovo T440p, I7-4600M. My old Laptop (Lenovo T420, i7 SNB) stays at pc7 ~ 98% when idle.

Are you using any power saving tool ?
I use Laptop Mode Tools.

Does your machine have a discrete graphics ?

[nkalkhof]

Are you using any power saving tool ?
I use Laptop Mode Tools.

Does your machine have a discrete graphics ?

Nope no descrete GPU.

And yes I'm using laptop mode tools. I also experimanted with powertop --autotune and a custom init script in hope to save some watts:

#!/sbin/runscript
start() {
ebegin "enabling powersave options"
# Enable Laptop-Mode disk writing
echo 5 > /proc/sys/vm/laptop_mode
#VM writeback timeout
echo 1500 > /proc/sys/vm/dirty_writeback_centisecs
# set SATA channel to power saving
for foo in /sys/class/scsi_host/host*/link_power_management_policy;
do echo min_power > $foo;
done
# Activate USB autosuspend
#for foo in /sys/bus/usb/devices/*/power/level;
#do echo auto > $foo;
#done
# Activate PCI autosuspend
for foo in /sys/bus/pci/devices/*/power/control;
do echo auto > $foo;
done
# Activate wlan powersave
iw dev wlp3s0 set power_save on
# Kill wake on lan
ethtool -s enp0s25 wol d
# Activate audio card power saving
echo 1 > /sys/module/snd_hda_intel/parameters/power_save
echo 1 > /sys/module/snd_hda_intel/parameters/power_save_controller
eend 0
}

[RickXy]

Nope no descrete GPU.

And yes I'm using laptop mode tools. I also experimanted with powertop --autotune and a custom init script in hope to save some watts:

#!/sbin/runscript
start() {
ebegin "enabling powersave options"
# Enable Laptop-Mode disk writing
echo 5 > /proc/sys/vm/laptop_mode
#VM writeback timeout
echo 1500 > /proc/sys/vm/dirty_writeback_centisecs
# set SATA channel to power saving
for foo in /sys/class/scsi_host/host*/link_power_management_policy;
do echo min_power > $foo;
done
# Activate USB autosuspend
#for foo in /sys/bus/usb/devices/*/power/level;
#do echo auto > $foo;
#done
# Activate PCI autosuspend
for foo in /sys/bus/pci/devices/*/power/control;
do echo auto > $foo;
done
# Activate wlan powersave
iw dev wlp3s0 set power_save on
# Kill wake on lan
ethtool -s enp0s25 wol d
# Activate audio card power saving
echo 1 > /sys/module/snd_hda_intel/parameters/power_save
echo 1 > /sys/module/snd_hda_intel/parameters/power_save_controller
eend 0
}

I'm not really sure then what your problem might be.

The thinkpads are usually pretty good compared to other devices. So, in a sane world, it should perform better on linux, than others.

But keep in mind that there are many many broken devices, including Lenovo's. For ex. I have a Lenovo Yoga 2 13, which has a bunch of USB devices claiming LPM, whereas in reality they are just buggy. As I write, I'm already almost done with root causing one of the flaky drivers with the linux-usb maintainers. Such devices, end up draining the power like anything.

It could very well be that you've been hit by a buggy device/driver.

[nkalkhof]

I'm not really sure then what your problem might be.

The thinkpads are usually pretty good compared to other devices. So, in a sane world, it should perform better on linux, than others.

But keep in mind that there are many many broken devices, including Lenovo's. For ex. I have a Lenovo Yoga 2 13, which has a bunch of USB devices claiming LPM, whereas in reality they are just buggy. As I write, I'm already almost done with root causing one of the flaky drivers with the linux-usb maintainers. Such devices, end up draining the power like anything.

It could very well be that you've been hit by a buggy device/driver.

Neither am I. The Laptop was always more power hungry approx 2 times when idle compared to windows 7 (with lenovo power tool installed). I've also disabled any device in the BIOS that I dont use, i.e. sdcard reader, bluetooth, wwan, camera, microphone. Right now I run a minimum configuration. idle power drain still jumped up with 4.7 approx 3 watts. I can't figure out why.
You're right Lenovo devices are pretty good tuned for low power mode compared with other vendors (espacially clevo *yack*). I guess I have to wait until the issue gets fixed somehow. Upgrading to skylake is out of the question right now. 2 hours, half a dozen i965 crashes on a t460s with 4.7.1 and drm-intel-git and I was ready to jump ship .