* Peter Zijlstra <a.p.zijls...@chello.nl> [2009-08-27 14:53:27]:
Hi Peter, Ben,
I've put the whole thing in a sort of a block diagram. Hope it
explains things more clearly.
----------------
| CPUIDLE | (Select idle states like
| GOVERNORS | C1, C1e, C6 etc in case
| (Menu/Ladder)| x86 & nap, snooze in
| | case of POWER - based on
---------------- latency & power req)
^
|
|
|
|
|
---------- ----------------- -------------
| | | | | PSERIES |
| ACPI |------------------> | CPUIDLE | <--------------| IDLE |
| | | | | |
---------- ----------------- -------------
Main idle routine- pm_idle() Main idle routine-
ppc_md.power_save()
pm_idle = cpuidle_pm_idle; ppc_md.power_save =
(start using cpuidle's idle cpuidle_pm_idle();
loop, which internally calls
governor to select the right
state to go into).
Relavent code snippet from drivers/cpuidle/cpuidle.c
-------------------------------------
static void cpuidle_idle_call(void)
{
............
............
/* Call the menu_select() to select the idle state to enter. */
next_state = cpuidle_curr_governor->select(dev);
............
............
/*
* Enter the idle state previously selected. target_state->enter
* would call pseries_cpuidle_loop() which selects nap/snooze
* /
dev->last_residency = target_state->enter(dev, target_state);
}
void cpuidle_install_idle_handler(void)
{
.........
.........
cpuidle_pm_idle = cpuidle_idle_call;
}
--arun
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
