Hi, I sort of managed to build a custom kernel before, though was a little short of space on my (SD card) boot/usr area, and have never applied a whole patch set.
What I'm mainly concerned about is: 1) What's the risk of actually *damaging* something trying to force HPET and C3/C4? 2) What extra power savings might a reasonably expect as a percentage? If, say, it is likely to be over 25% (eg 5W+) then it should be worth doing. It's all about potential risk/reward! (Oh, and I seem to have to repair some of *my* code in the NTP daemon, so, yes, I probably will try rebuilding it so I can provide stratum-1 service again, though it's a *long* way down the list of waker-upers... B^> ) Rgds Damon On 4 Aug 2007, at 16:24, Russell Harmon wrote: > My suggestion here would be to make your own kernel. There are lots of > patches that you can use (hpet, C3) to save power. Also, according to > http://www.linuxpowertop.org/known.php#ntp NTP generates wakeups when > it shouldn't. You should compile that from patched source and install > yourself. Maybe have a look at http://www.linuxpowertop.org/known.php > and see if there is anything else you can do. > > Personally, I find that gentoo can do almost all of that for me, so > that is what i'd recommend for ease of use (it's what I use). If you > already have a production system however, it's probably not worthwhile > to redo it. > > On 8/4/07, Damon Hart-Davis <[EMAIL PROTECTED]> wrote: >> [Sorry if this gets through twice: I messed up last time...] >> >> Hi, >> >> I have moved a whole bunch of servers off a rack of Solaris machines >> and onto a single Linux laptop which I am trying to run on low-enough >> power to run off solar PV for as much of the time as possible (see >> http://www.earth.org.uk/low-power-laptop.html) and total power use >> has come down from ~670W to <30W on mains (<20W powered from solar PV >> via an efficient DC/DC converter). >> >> But I'm not sure how far further I can push the h/w I have. >> >> For example, it doesn't show C3 or C4 states available which is a >> shame since it is 99% idle (most time is spent in C2). >> >> Also, it doesn't show HPET as being available, which results in ~50 >> extra wakeups per second. >> >> Now I *am* running a bunch of DNS, NTP, SMTP, and HTTP servers on >> that (Core Duo T2250) machine, albeit quiet ones, that generate ~30+ >> wakeups per second themselves legitimately. >> >> Is it worth trying to force activate HPET, C3 ad C4? >> >> How can I safely do it if so? I have looked at the BIOS with >> dmidecode and biosdecode, and don't get any great clues. >> >> I have played with building a previous kernel but am now simply >> running a stock (22-rc7) Ubuntu "Gutsy" kernel in my "Feisty" system. >> >> I am using cpufreqd/ondemand which I have tuned as good as I can get >> (quick builds, idles in lowest freq ~99%). >> >> I am using laptop-mode. >> >> And of course I have used powertop to help tune userspace and >> cpufreqd, which is why I am here! >> >> Rgds >> >> Damon >> >> >> _______________________________________________ >> Power mailing list >> [email protected] >> http://www.bughost.org/mailman/listinfo/power >> > > > -- > Go read my blog: http://eatnumber1.blogspot.com/ > _______________________________________________ Power mailing list [email protected] http://www.bughost.org/mailman/listinfo/power
