Re: [systemd-devel] systemd and power management
On Wed, 29.10.14 13:00, Daniel Hollocher (danielholloc...@gmail.com) wrote: Hey folks, I'm a not expert here, so please forgive the low quality/interest of my question. I'm curious what the ideal systemd way is to set various power management settings in the /sys tree. For me personally, I'm looking to set sampling_down_factor as without it, ondemand has terrible performance on my particular computer (a 10-30% loss compared to performance or conservative). Currently, Ubuntu uses a sysv init script to set ondemand after boot, and I could edit that. It would be cool to know the ideal systemd way, that could also be aware of power saving stuff. From googling, it seems that tempfiles or sysctrl is not the way to go, since those only happen at boot. Udev? The examples I've found seem to make basic usage of udev to detect power changes, and then drop to a script to do the bulk of the work. Is that it? Yes, sysctl.d and tmpfiles.d (with the f option) are the way we propose this is done. Note that in general we try to follow the rule that what is good for mobile use cannot hurt in plugged-in mode either, hence we have no special support for reconfiguring the system depending on plug state. systemd does not listen to power plug events. upower does however, hence you could check if you can hook things into that. Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd and power management
On Wed, Oct 29, 2014 at 01:00:42PM -0400, Daniel Hollocher wrote: Hey folks, I'm a not expert here, so please forgive the low quality/interest of my question. I'm curious what the ideal systemd way is to set various power management settings in the /sys tree. For me personally, I'm looking to set sampling_down_factor as without it, ondemand has terrible performance on my particular computer (a 10-30% loss compared to performance or conservative). Currently, Ubuntu uses a sysv init script to set ondemand after boot, and I could edit that. It would be cool to know the ideal systemd way, that could also be aware of power saving stuff. From googling, it seems that tempfiles or sysctrl is not the way to go, since those only happen at boot. Udev? The examples I've found seem to make basic usage of udev to detect power changes, and then drop to a script to do the bulk of the work. Is that it? See sysctl.d(5). Zbyszek ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd and power management
On Wednesday 29 October 2014 at 13:00:42, Daniel Hollocher wrote: Hey folks, I'm a not expert here, so please forgive the low quality/interest of my question. I'm curious what the ideal systemd way is to set various power management settings in the /sys tree. For me personally, I'm looking to set sampling_down_factor as without it, ondemand has terrible performance on my particular computer (a 10-30% loss compared to performance or conservative). Currently, Ubuntu uses a sysv init script to set ondemand after boot, and I could edit that. It would be cool to know the ideal systemd way, that could also be aware of power saving stuff. From googling, it seems that tempfiles or sysctrl is not the way to go, since those only happen at boot. Udev? The examples I've found seem to make basic usage of udev to detect power changes, and then drop to a script to do the bulk of the work. Is that it? You could write a bunch of units pulled in by a target... well, two targets, one for power-saving and second for performance mode. And then just start the targets from an udev rule. Just remember to use `--no-block` as udev kills workers after some time. I've already done something along these lines for my own purposes, see https://github.com/intelfx/power-management However, I still want to know if I this is OK wrt systemd spirit. -- Ivan Shapovalov / intelfx / signature.asc Description: This is a digitally signed message part. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] systemd and power management
Yeah, it's tricky. I don't think sysctl is the answer as that doesn't work with /sys On Wed, Oct 29, 2014 at 1:06 PM, Ivan Shapovalov intelfx...@gmail.com wrote: On Wednesday 29 October 2014 at 13:00:42, Daniel Hollocher wrote: Hey folks, I'm a not expert here, so please forgive the low quality/interest of my question. I'm curious what the ideal systemd way is to set various power management settings in the /sys tree. For me personally, I'm looking to set sampling_down_factor as without it, ondemand has terrible performance on my particular computer (a 10-30% loss compared to performance or conservative). Currently, Ubuntu uses a sysv init script to set ondemand after boot, and I could edit that. It would be cool to know the ideal systemd way, that could also be aware of power saving stuff. From googling, it seems that tempfiles or sysctrl is not the way to go, since those only happen at boot. Udev? The examples I've found seem to make basic usage of udev to detect power changes, and then drop to a script to do the bulk of the work. Is that it? You could write a bunch of units pulled in by a target... well, two targets, one for power-saving and second for performance mode. And then just start the targets from an udev rule. Just remember to use `--no-block` as udev kills workers after some time. I've already done something along these lines for my own purposes, see https://github.com/intelfx/power-management However, I still want to know if I this is OK wrt systemd spirit. -- Ivan Shapovalov / intelfx / ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
