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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-05-10 01:19:52 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-05-14 21:37:52 +0200 |
| commit | 0d94039fabccaa81d87eafdac509d0dda4df2f7b (patch) | |
| tree | 3b7697a35df7ca25b0e9d013b68a2e2702ddb465 /drivers/cpuidle | |
| parent | 827a5aefc542b8fb17c00de06118e5cd0e3800f2 (diff) | |
| download | talos-obmc-linux-0d94039fabccaa81d87eafdac509d0dda4df2f7b.tar.gz talos-obmc-linux-0d94039fabccaa81d87eafdac509d0dda4df2f7b.zip | |
cpuidle: Select a different state on tick_broadcast_enter() failures
If tick_broadcast_enter() fails in cpuidle_enter_state(),
try to find another idle state to enter instead of invoking
default_idle_call() immediately and returning -EBUSY which
should increase the chances of saving some energy in those
cases.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index a7b9e679a2ef..af6dd599c464 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -73,7 +73,10 @@ int cpuidle_play_dead(void) } static int find_deepest_state(struct cpuidle_driver *drv, - struct cpuidle_device *dev, bool freeze) + struct cpuidle_device *dev, + unsigned int max_latency, + unsigned int forbidden_flags, + bool freeze) { unsigned int latency_req = 0; int i, ret = freeze ? -1 : CPUIDLE_DRIVER_STATE_START - 1; @@ -83,6 +86,8 @@ static int find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_state_usage *su = &dev->states_usage[i]; if (s->disabled || su->disable || s->exit_latency <= latency_req + || s->exit_latency > max_latency + || (s->flags & forbidden_flags) || (freeze && !s->enter_freeze)) continue; @@ -100,7 +105,7 @@ static int find_deepest_state(struct cpuidle_driver *drv, int cpuidle_find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev) { - return find_deepest_state(drv, dev, false); + return find_deepest_state(drv, dev, UINT_MAX, 0, false); } static void enter_freeze_proper(struct cpuidle_driver *drv, @@ -139,7 +144,7 @@ int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev) * that interrupts won't be enabled when it exits and allows the tick to * be frozen safely. */ - index = find_deepest_state(drv, dev, true); + index = find_deepest_state(drv, dev, UINT_MAX, 0, true); if (index >= 0) enter_freeze_proper(drv, dev, index); @@ -168,8 +173,13 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, * CPU as a broadcast timer, this call may fail if it is not available. */ if (broadcast && tick_broadcast_enter()) { - default_idle_call(); - return -EBUSY; + index = find_deepest_state(drv, dev, target_state->exit_latency, + CPUIDLE_FLAG_TIMER_STOP, false); + if (index < 0) { + default_idle_call(); + return -EBUSY; + } + target_state = &drv->states[index]; } /* Take note of the planned idle state. */ |
