power management experiences with joyride-1572

[Frank Ch. Eigler]

Chris Ball <cjb at laptop.org> writes:

> [...]
> In the future, we can imagine setting wakeups programmatically, with
> the help of the Linux dynamic ticks implementation and the cpuidle
> framework -- if Frank's sugar clock has a pending wakeup in 60 seconds
> to update the minute hand of the clock, we can set a wakeup for +59s
> before going to sleep.  This is a long-term feature, though.

To what extent do folks know what olpc userspace is doing in its idle
moments?  If there is not much junk system call traffic, one could
imagine a tool that monitors the processes, and when it finds that
they're all voluntarily sleeping for "long enough", it could schedule
an early suspend and a later automatic resume.  i.e., if sugar clock
is doing sleep(60), but other processes are blocked on I/O, this
tool could run "rtcwakeup 60; echo mem > /proc/.../suspend").

- FChE