[Bug 464570] Re: initscripts forces ondemand CPU governor 60 seconds after boot

[Søren Holm]

When on AC the default should be performance, not ondemand. Why is it default ?

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Title:
  initscripts forces ondemand CPU governor 60 seconds after boot

Status in “sysvinit” package in Ubuntu:
  Won't Fix

Bug description:
  Binary package hint: sysvinit

  Related to bug 434257.

  Karmic has script /etc/init.d/ondemand installed by default. The
  script is automatically executed during the boot and it sleeps for 60
  seconds and then forces all CPU cores to use "ondemand" cpufreq
  governor.

  This should be changed. Reasons:

  (1) This causes poor performance. I can see visible difference with
  normal desktop usage between "performance" and "ondemand" governors.
  It does not make sense to force poor performance for everybody. (The
  issue for poor performance is highly probably that the "ondemand"
  governor is too slow to scale the frequence upwards once the user
  executes anything in totally idle computer. Basically the latency is
  too high.) The Ubuntu does not boot with performance governor by
  accident!

  (2) Because this script is included in the "initscripts" package, this
  script will be used with linux-rt and linux-server packages.
  Especially with linux-rt it hurts! Also, see the commend in the
  /etc/init.d/ondemand - it clearly is designed for desktop use only and
  should not used on server. And I'm claiming that it does not make
  sense even on desktop.

  (3) Because the script sleeps for 60 seconds (which is a
  random/arbitrary time from the user's point of view) before it
  executes the payload, it will be hard to figure out why the CPU
  governor suddenly changes. I tried to put stuff in /etc/rc.local to
  force performance governor and I was very unhappy to find the CPU
  governor still changing.

  Suggested fix:
  If Ubuntu really wants to keep this script for some reason, it should be put into a separate package that is recommended by ubuntu-desktop. That way, the behavior can be easily removed.
  As an alternative, the /etc/init.d/ondemand script should look at /etc/default/ondemand.conf (or perhaps /etc/default/cpufreq) and use settings defined there. That way, the user can select other CPU governor but ondemand.

  Other notes:
  The CPU frequence does not matter much if the CPU can use C1 or lower power saving states. It makes much more sense to run at the highest possible speed ("performance") when there's something to do so that the CPU can enter real power saving modes faster. Perhaps there should be an additional CPU governor that is identical to performance except the fact, that it changes to lowest freqency when entering C1 or lower and changes to highest frequence when entering C0. I'm a bit skeptical if that saves any power compared to "performance" all the time, but it could be tested.

  ProblemType: Bug
  Architecture: amd64
  Date: Fri Oct 30 11:33:00 2009
  DistroRelease: Ubuntu 9.10
  InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release Candidate amd64 (20091020.3)
  Package: initscripts 2.87dsf-4ubuntu11
  ProcEnviron:
   PATH=(custom, user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcVersionSignature: Ubuntu 2.6.31-9.152-rt
  SourcePackage: sysvinit
  Uname: Linux 2.6.31-9-rt x86_64
  XsessionErrors:
   (gnome-settings-daemon:13661): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
   (gnome-settings-daemon:13661): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
   (polkit-gnome-authentication-agent-1:14378): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
   (nautilus:14212): Eel-CRITICAL **: eel_preferences_get_boolean: assertion `preferences_is_initialized ()' failed
   (gnome-panel:14194): Gdk-WARNING **: /build/buildd/gtk+2.0-2.18.3/gdk/x11/gdkdrawable-x11.c:952 drawable is not a pixmap or window

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