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| author | Ramesh Thomas <ramesh.thomas@intel.com> | 2017-10-27 05:01:34 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-11-08 14:16:01 +0300 |
| commit | c523c68da2117a3f9f777110839b1cf7ed7221be (patch) | |
| tree | 2b06b4593e6af9d9614fc8a4c4c1d41f88eb1144 /drivers/cpuidle | |
| parent | 4e37fd4d5dfd39f547b0b00fa184a440a1e44b96 (diff) | |
| download | linux-c523c68da2117a3f9f777110839b1cf7ed7221be.tar.xz | |
cpuidle: ladder: Add per CPU PM QoS resume latency support
Individual CPUs may have special requirements to not enter
deep idle states. For example, a CPU running real time
applications would not want to enter deep idle states to
avoid latency impacts. At the same time other CPUs that
do not have such a requirement could allow deep idle
states to save power.
This was already implemented in the menu governor.
Implementing similar changes in the ladder governor which
gets selected when CONFIG_NO_HZ and CONFIG_NO_HZ_IDLE are not
set. Refer following commits for the menu governor changes.
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/governors/ladder.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c index ce1a2ffffb2a..1ad8745fd6d6 100644 --- a/drivers/cpuidle/governors/ladder.c +++ b/drivers/cpuidle/governors/ladder.c @@ -17,6 +17,7 @@ #include <linux/pm_qos.h> #include <linux/jiffies.h> #include <linux/tick.h> +#include <linux/cpu.h> #include <asm/io.h> #include <linux/uaccess.h> @@ -67,10 +68,16 @@ static int ladder_select_state(struct cpuidle_driver *drv, struct cpuidle_device *dev) { struct ladder_device *ldev = this_cpu_ptr(&ladder_devices); + struct device *device = get_cpu_device(dev->cpu); struct ladder_device_state *last_state; int last_residency, last_idx = ldev->last_state_idx; int first_idx = drv->states[0].flags & CPUIDLE_FLAG_POLLING ? 1 : 0; int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY); + int resume_latency = dev_pm_qos_raw_read_value(device); + + if (resume_latency < latency_req && + resume_latency != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) + latency_req = resume_latency; /* Special case when user has set very strict latency requirement */ if (unlikely(latency_req == 0)) { |