(01-17-2020, 11:53 AM)danielt Wrote: Anything running Debian Bullseye is, assuming you used my installer and didn't change it afterwards, configured to do something called suspend-to-idle.

It means that when the laptop is asked to suspend to memory the kernel will prevent any tasks from being scheduled and close down most of the device drivers. Then it just waits... in other words is relies on normal kernel power management (cpufreq, cpuidle, etc) to minimise standby power. In principle by eliminating wakeups then we ensure that cpuidle can descend to it's deepest sleep state.

(01-17-2020, 11:53 AM)danielt Wrote: Anything running Debian Bullseye is, assuming you used my installer and didn't change it afterwards, configured to do something called suspend-to-idle.

It means that when the laptop is asked to suspend to memory the kernel will prevent any tasks from being scheduled and close down most of the device drivers. Then it just waits... in other words is relies on normal kernel power management (cpufreq, cpuidle, etc) to minimise standby power. In principle by eliminating wakeups then we ensure that cpuidle can descend to it's deepest sleep state.

There are some power savings in this state (for example all the radios will get turned off) but they are pretty modest. I compared an s2idle system against a system doing nothing with the backlight turned off... s2idle ended up saving about a watt. So, not completely useless, but if I am going away for more than an hour I generally do a real power off instead.

It is configured this way because I wasn't able to get the system to turn back on after going into a deeper suspend state. There are some power savings but more importantly the laptop shouldn't hang when you close the lid: most desktop environments are configured to automatically suspend on lid-close and adopting s2idle means we don't have to hack each one separately to avoid the suspend.

(01-21-2020, 10:10 AM)wasgurd Wrote:

(01-17-2020, 11:53 AM)danielt Wrote: Anything running Debian Bullseye is, assuming you used my installer and didn't change it afterwards, configured to do something called suspend-to-idle.

It means that when the laptop is asked to suspend to memory the kernel will prevent any tasks from being scheduled and close down most of the device drivers. Then it just waits... in other words is relies on normal kernel power management (cpufreq, cpuidle, etc) to minimise standby power. In principle by eliminating wakeups then we ensure that cpuidle can descend to it's deepest sleep state.

There are some power savings in this state (for example all the radios will get turned off) but they are pretty modest. I compared an s2idle system against a system doing nothing with the backlight turned off... s2idle ended up saving about a watt. So, not completely useless, but if I am going away for more than an hour I generally do a real power off instead.

It is configured this way because I wasn't able to get the system to turn back on after going into a deeper suspend state. There are some power savings but more importantly the laptop shouldn't hang when you close the lid: most desktop environments are configured to automatically suspend on lid-close and adopting s2idle means we don't have to hack each one separately to avoid the suspend.

Could you clarify please, how to change s2idle to suspend to ram/disk? I want to test how it works for me.

Quote:/etc/tmpfiles.d/force-s2idle.conf

Quote:cat /sys/power/mem_sleep

Quote:s2idle [deep]

Quote:echo deep > /sys/power/mem_sleep

Quote:echo deep > /sys/power/state
or try (if mem_sleep was set to deep upon reboot)
systemctl suspend

Quote:sudo journalctl |grep suspend