On 05/15/2013 05:24 PM, Liviu Dudau wrote:
Hi Sebastian,
On Mon, May 13, 2013 at 07:53:42PM +0100, Sebastian Capella wrote:
Pass residency information to the mcpm_cpu_suspend. The information is taken from the target_residency of the intended C-state.
When a platform uses multiple powerdown cstates, the residency information indicates which powerdown state is targeted. Multiple powerdown cstate information can be maintained in the device tree and the vendor specific handling will then have enough information to determine what power state to enter without needing additional changes to the big_little framework.
Signed-off-by: Sebastian Capella sebastian.capella@linaro.org
drivers/cpuidle/arm_big_little.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/cpuidle/arm_big_little.c b/drivers/cpuidle/arm_big_little.c index a430800..8332b05 100644 --- a/drivers/cpuidle/arm_big_little.c +++ b/drivers/cpuidle/arm_big_little.c
I could not find a branch that contains this file. Which git tree and branch are you using?
I believe it should apply to:
https://git.linaro.org/gitweb?p=landing-teams/working/arm/kernel.git%3Ba=blo...
@@ -89,7 +89,7 @@ static int notrace bl_powerdown_finisher(unsigned long arg) unsigned int cpu = mpidr & 0xf;
mcpm_set_entry_vector(cpu, cluster, cpu_resume);
mcpm_cpu_suspend(0); /* 0 should be replaced with better value here */
mcpm_cpu_suspend(arg); return 1;}
@@ -107,6 +107,7 @@ static int bl_enter_powerdown(struct cpuidle_device *dev, { struct timespec ts_preidle, ts_postidle, ts_idle; int ret;
struct cpuidle_state *state = &drv->states[idx]; /* Used to keep track of the total time in idle */ getnstimeofday(&ts_preidle);@@ -117,7 +118,8 @@ static int bl_enter_powerdown(struct cpuidle_device *dev,
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
ret = cpu_suspend((unsigned long) dev, bl_powerdown_finisher);
ret = cpu_suspend((unsigned long) state->target_residency,bl_powerdown_finisher);I don't think you should pass the target residency here but the intended C-state. Think about what will happen when you run this in a guest kernel: is the target_residency the same if the guest has been migrated from a big core that might have a faster execution of the down/up path to a little core that is slower? The intended C-state should stay the same, regardless of the actual time it takes to get there and out, which affects the actual time spent inside the state.
Best regards, Liviu