On Sun, Sep 04, 2016 at 08:53:41PM +0100, Ed Batalha wrote: > Hi, > > While researching how to get my laptop to save a bit more power in battery > mode > I found a great hint at > http://www.neowin.net/forum/topic/1106745-howto-powersaving-tweaks-with-a-udev-rule/ > which will fit nicely into LFS section 7.4 . >
Just a couple of comments - > # > # sound card powersave > # echo 10 > /sys/module/snd_hda_intel/parameters/power_save > # echo Y > /sys/module/snd_hda_intel/parameters/power_save_controller > # > # wlan0 powersave > # iwconfig wlan0 power on &> /dev/null > # I use things based on an older suggestion (I think it was the original 'laptop mode' script, but I might be mistaken. But I don't think I do anything for the sound or wifi. Do these make a significant difference ? My own laptop is actually a netbook, and so short of RAM that I don't think I'll ever rebuild LFS on it. But I'll try to remember this post when I eventually get a newer laptop, so thanks for mentioning these and providing the link. But: > # cpufreq powersave > echo powersave > /sys/bus/cpu/devices/cpu0/cpufreq/scaling_governor > ;; ... > # > # cpufreq ondemand > echo ondemand > /sys/bus/cpu/devices/cpu0/cpufreq/scaling_governor > ;; Cpufreq isn't something we really cover in LFS or BLFS. But I've been using it for years. I think that powersave works on all current governors and all recent processors, but on intel (probably core and later, certainly SandyBridge and later) the preferred governor is pstate - and that doesn't do 'ondemand' (for SandyBridge and Haswell desktops, 'performance' appears to be satisfactory in terms of power drain, although the reported CPU frequency doesn't seem to drop down the way it used to). Similarly on AMD the pstate governor has been the default for some time - unless I'm mistaken. ĸen -- `I shall take my mountains', said Lu-Tze. `The climate will be good for them.' -- Small Gods -- http://lists.linuxfromscratch.org/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page Do not top post on this list. A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? http://en.wikipedia.org/wiki/Posting_style
