cpuidle/x86/perf: fix power:cpu_idle double end events and throw cpu_idle events from the cpuidle layerlinaro-linux-2.6.37-upstream-27Jan2011

Currently intel_idle and acpi_idle driver show double cpu_idle "exit idle"
events -> this patch fixes it and makes cpu_idle events throwing less complex.

It also introduces cpu_idle events for all architectures which use
the cpuidle subsystem, namely:
  - arch/arm/mach-at91/cpuidle.c
  - arch/arm/mach-davinci/cpuidle.c
  - arch/arm/mach-kirkwood/cpuidle.c
  - arch/arm/mach-omap2/cpuidle34xx.c
  - arch/drivers/acpi/processor_idle.c (for all cases, not only mwait)
  - arch/x86/kernel/process.c (did throw events before, but was a mess)
  - drivers/idle/intel_idle.c (did throw events before)

Convention should be:
Fire cpu_idle events inside the current pm_idle function (not somewhere
down the the callee tree) to keep things easy.

Current possible pm_idle functions in X86:
c1e_idle, poll_idle, cpuidle_idle_call, mwait_idle, default_idle
-> this is really easy is now.

This affects userspace:
The type field of the cpu_idle power event can now direclty get
mapped to:
/sys/devices/system/cpu/cpuX/cpuidle/stateX/{name,desc,usage,time,...}
instead of throwing very CPU/mwait specific values.
This change is not visible for the intel_idle driver.
For the acpi_idle driver it should only be visible if the vendor
misses out C-states in his BIOS.
Another (perf timechart) patch reads out cpuidle info of cpu_idle
events from:
/sys/.../cpuidle/stateX/*, then the cpuidle events are mapped
to the correct C-/cpuidle state again, even if e.g. vendors miss
out C-states in their BIOS and for example only export C1 and C3.
-> everything is fine.

Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: Robert Schoene <robert.schoene@tu-dresden.de>
CC: Jean Pihet <j-pihet@ti.com>
CC: Arjan van de Ven <arjan@linux.intel.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: linux-pm@lists.linux-foundation.org
CC: linux-acpi@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-perf-users@vger.kernel.org
CC: linux-omap@vger.kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
(based on mainline commit f77cfe4ea2)

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 08d5f05378d..491a4af2349 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -96,7 +96,15 @@ static void cpuidle_idle_call(void)
 
 	/* enter the state and update stats */
 	dev->last_state = target_state;
+
+	trace_power_start(POWER_CSTATE, next_state, dev->cpu);
+	trace_cpu_idle(next_state, dev->cpu);
+
 	dev->last_residency = target_state->enter(dev, target_state);
+
+	trace_power_end(dev->cpu);
+	trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);
+
 	if (dev->last_state)
 		target_state = dev->last_state;
 
@@ -106,8 +114,6 @@ static void cpuidle_idle_call(void)
 	/* give the governor an opportunity to reflect on the outcome */
 	if (cpuidle_curr_governor->reflect)
 		cpuidle_curr_governor->reflect(dev);
-	trace_power_end(smp_processor_id());
-	trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
 }
 
 /**