Graham Smith wrote: > Firstly I want to thank every involved in this. I am a techno geek and > also an environmentalist. > > I would like to suggest we provide an easier to follow guide for non > geeks who want to reduce the power their computers are using. My wife > teaches at a non profit school. They use Linux and they would like to do > their part to reduce global warming. However they are completely baffled > by tips like this > > "interrupt > acpi is taking 15-20 wakeups. > Setting /proc/acpi/thermal_zone/THZN/polling_frequency to 0 instead of 2 > solves this." > > Sorry to pick on this one item, but most tips are very hard to follow > unless you have a BS in computer science. I had to google search this > one myself, so not much chance of a 2 grade teacher following this. > > It would be great if someone could spend a few cycle and add some text > on how to enact the guidance. > That's self explanatory - if you've ever changed any other setting in sysfs or procfs. No University education required :-). The _most_ friendly solution would be to incorporate it as a tip in powertop. After correcting "THZM" to "THRM"... sigh.
But yes, it would be better to match e.g. the S06cpuspeed entry, and say "If acpi is generating 15-20 wake-ups, you can fix this from the command prompt with the following command: echo 0 > /proc/acpi/thermal_zone/THRM/polling_frequency" On the other hand, you missed the even more cryptic warning at the end of the tip: "Important: Keep temperature of thermal zone on watch!" If the kernel was polling the thermal zone once every 2 seconds, that's probably because the ACPI BIOS said that was necessary (because the system doesn't generate temperature-change events). Disabling polling completely opens the possibility that the temperature of the thermal zone will rise above the danger point undetected. So your cpu might fry. Which means it would be much safer to set a longer polling interval, e.g 10 seconds, instead of disabling it altogether. How about this? Disclaimer: I don't have such a system, and I don't have a laptop so I haven't worried much about overheat myself. "If acpi is generating 15-20 wake-ups, check for thermal zone polling. You can do this from the command prompt with the following command, which will either say "<polling disabled>" or give the polling frequency in seconds: cat /proc/acpi/thermal_zone/THRM/polling_frequency If polling is disabled by default, thermal zone polling isn't the problem. If the value is quite high, e.g. 2, you can increase it e.g. to 10 seconds with echo 10 > /proc/acpi/thermal_zone/THRM/polling_frequency or disable it altogether by setting it to 0. Note that the thermal zone is the ACPI mechanism for monitoring CPU temperature. Be aware that if you disable polling or increase the polling interval too much, ACPI may not be able to detect when your CPU is overheating in time to cool it down. Permanent damage could result." _______________________________________________ Power mailing list [email protected] http://www.bughost.org/mailman/listinfo/power
