Re: [v8 PATCH 1/8]: cpuidle: cleanup drivers/cpuidle/cpuidle.c

* Balbir Singh [off-list ref] [2009-10-12 17:06:02]:

* Arun R B [off-list ref] [2009-10-08 15:19:42]:

quoted

* Arun R Bharadwaj [off-list ref] [2009-10-08 15:18:28]:

This patch cleans up drivers/cpuidle/cpuidle.c
Earlier cpuidle assumed pm_idle as the default idle loop. Break that
assumption and make it more generic. cpuidle_idle_call() which is the
main idle loop of cpuidle is to be called by architectures which have
registered to cpuidle.

Remove routines cpuidle_install/uninstall_idle_handler() which are not
needed anymore.

[snip]

  /**

quoted

- * cpuidle_install_idle_handler - installs the cpuidle idle loop handler
- */
-void cpuidle_install_idle_handler(void)
-{
-	if (enabled_devices && (pm_idle != cpuidle_idle_call)) {
-		/* Make sure all changes finished before we switch to new idle */
-		smp_wmb();
-		pm_idle = cpuidle_idle_call;
-	}
-}
-
-/**
- * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler
- */
-void cpuidle_uninstall_idle_handler(void)
-{
-	if (enabled_devices && pm_idle_old && (pm_idle != pm_idle_old)) {
-		pm_idle = pm_idle_old;
-		cpuidle_kick_cpus();
-	}
-}
-

I see the routines above being called in from
cpuidle_pause/resume_and_lock/unlock below and they are entries from
ACPI on ACPI_PROCESSOR_NOTIFY_POWER and from the hotplug path, could
you test them to make sure they are not broken. We also seem to be
missing a cpuidle_kick_cpus() in cpuidle_pause_and_lock()

[snip]

Hi Balbir,

yes, we definitely need a cpuidle_kick_cpus() in
cpuidle_pause_and_lock() since this is used while disabling the
cpuidle_device and the cpus need to be kicked out of the idle states.
I will test this modified code and see if it breaks hotplug.

thanks,
arun

-- 
	Balbir