linux-toradex.git/drivers/cpuidle, branch v2.6.27.50

cpuidle: Add decaying history logic to menu idle predictor

2009-02-06T22:00:40+00:00

commit 816bb611e41be29b476dc16f6297eb551bf4d747 upstream

Add decaying history of predicted idle time, instead of using the last early
wakeup. This logic helps menu governor do better job of predicting idle time.

With this change, we also measured noticable (~8%) power savings on
a DP server system with CPUs supporting deep C states, when system
was lightly loaded. There was no change to power or perf on other load
conditions.

Signed-off-by: Venkatesh Pallipadi 
Signed-off-by: Len Brown 
Cc: Thomas Renninger 
Signed-off-by: Greg Kroah-Hartman

cpuidle: use last_state which can reflect the actual state entered

2009-02-06T22:00:40+00:00

commit 887e301aa1105326f1412a98749024263b1031c7 upstream

cpuidle accounts the idle time for the C-state it was trying to enter and
not to the actual state that the driver eventually entered. The driver may
select a different state than the one chosen by cpuidle due to
constraints like bus-mastering, etc.

Change the time acounting code to look at the dev->last_state after
returning from target_state->enter(). Driver can modify dev->last_state
internally, inside the enter routine to reflect the actual C-state
entered.

Signed-off-by: Venkatesh Pallipadi 
Tested-by: Kevin Hilman 
Signed-off-by: Len Brown 
Cc: Thomas Renninger 
Signed-off-by: Greg Kroah-Hartman

cpuidle: upon BIOS bug, default to default_idle rather than polling

2009-02-06T22:00:40+00:00

commit 89cedfefca1d446ee2598fd3bcbb23ee3802e26a upstream

http://bugzilla.kernel.org/show_bug.cgi?id=11345

Signed-off-by: Venkatesh Pallipadi 
Signed-off-by: Len Brown 
Cc: Thomas Renninger 
Signed-off-by: Greg Kroah-Hartman

cpuidle: Make ladder governor honor latency requirements fully

2008-08-15T19:25:35+00:00

ladder governor only honored latency requirement when promoting C-states.
Instead. it should check for latency requirement on each idle call,
and demote to appropriate C-state when there is a latency requirement change.

Signed-off-by: Venkatesh Pallipadi 
Signed-off-by: Andi Kleen

cpuidle: Menu governor fix wrong usage of measured_us

2008-08-15T19:25:25+00:00

There is a bug in menu governor where we have
		if (data->elapsed_us < data->elapsed_us + measured_us)

with measured_us already having elapsed_us added in tickless case here
	unsigned int measured_us =
		cpuidle_get_last_residency(dev) + data->elapsed_us;

Also, it should be last_residency, not measured_us, that need to be used to
do comparing and distinguish between expected & non-expected events.

Refactor menu_reflect() to fix these two problems.

Signed-off-by: Venkatesh Pallipadi 
Signed-off-by: Wei Gang 
Signed-off-by: Andi Kleen

cpuidle: Do not use poll_idle unless user asks for it

2008-08-15T19:25:25+00:00

poll_idle was added to CPUIDLE, just as a low latency idle handler, to be
used in cases when user desires CPUs not to enter any idle state at all. It
was supposed to be a run time idle=poll option to the user. But, it was indeed
getting used during normal menu and ladder governor default case, with no
special user setting (Reported by Linus Torvalds).

Change below ensures that poll_idle will not be used unless user explicitly
asks pm_qos infrastructure for zero latency requirement.

Signed-off-by: Venkatesh Pallipadi 
Signed-off-by: Andi Kleen

cpuidle: make sysfs attributes sysdev class attributes

2008-08-12T23:07:28+00:00

These attributes are really sysdev class attributes.  The incorrect
definition leads to an oops because of recent changes which make sysdev
attributes use a different prototype.

Based on Andi's f718cd4add5aea9d379faff92f162571e356cc5f ("sched: make
scheduler sysfs attributes sysdev class devices")

Reported-by: Eric Sesterhenn 
Signed-off-by: Rabin Vincent 
Acked-by: Andi Kleen 
Cc: "Li, Shaohua" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ACPI/CPUIDLE: prevent setting pm_idle to NULL

2008-07-28T15:31:58+00:00

pm_idle_save resp. pm_idle_old can be NULL when the restore code in
acpi_processor_cst_has_changed() resp. cpuidle_uninstall_idle_handler()
is called. This can set pm_idle unconditinally to NULL, which causes the
kernel to panic when calling pm_idle in the x86 idle code. This was
covered by an extra check for !pm_idle in the x86 idle code, which was
removed during the x86 idle code refactoring.

Instead of restoring the pm_idle check in the x86 code prevent the
acpi/cpuidle code to set pm_idle to NULL.

Reported by: Dhaval Giani http://lkml.org/lkml/2008/7/2/309
Based on a debug patch from Ingo Molnar

Signed-off-by: Thomas Gleixner 
Signed-off-by: Linus Torvalds

sysdev: Pass the attribute to the low level sysdev show/store function

2008-07-22T04:55:02+00:00

This allow to dynamically generate attributes and share show/store
functions between attributes. Right now most attributes are generated
by special macros and lots of duplicated code. With the attribute
passed it's instead possible to attach some data to the attribute
and then use that in shared low level functions to do different things.

I need this for the dynamically generated bank attributes in the x86
machine check code, but it'll allow some further cleanups.

I converted all users in tree to the new show/store prototype. It's a single
huge patch to avoid unbisectable sections.

Runtime tested: x86-32, x86-64
Compiled only: ia64, powerpc
Not compile tested/only grep converted: sh, arm, avr32

Signed-off-by: Andi Kleen 
Signed-off-by: Greg Kroah-Hartman

smp_call_function: get rid of the unused nonatomic/retry argument

2008-06-26T09:24:35+00:00

It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.

Acked-by: Jeremy Fitzhardinge 
Signed-off-by: Jens Axboe