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authorAlex Shi <alex.shi@linaro.org>2017-01-12 21:27:04 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-01-30 11:03:32 +0100
commit9908859acaa95640d4a07991a93f7cd5bfc18e02 (patch)
tree4606265c8d2ea8ab3cea9c09c2f44aaf3604515c /drivers/cpuidle
parent8e37e1a2a3295f5d99e6dbe99eca24eca7a034ef (diff)
cpuidle/menu: add per CPU PM QoS resume latency consideration
There may be special requirements on CPU response time, like if a interrupt is pinned to a CPU, that CPU should not go into excessively deep idle states. For this reason, add a mechanism for adding PM QoS resume latency constraints for individual CPUs and modify the menu governor to take them into account. To that end, extend the device PM QoS pm_qos_resume_latency attribute to CPUs, which is possible, because the exit latency for CPUs is effectively equivalent to the resume latency for devices. Signed-off-by: Alex Shi <alex.shi@linaro.org> Acked-by: Rik van Riel <riel@redhat.com> [ rjw : Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/governors/menu.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 07e36bb54006..8d6d25c38c02 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -19,6 +19,7 @@
#include <linux/tick.h>
#include <linux/sched.h>
#include <linux/math64.h>
+#include <linux/cpu.h>
/*
* Please note when changing the tuning values:
@@ -280,17 +281,23 @@ again:
static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
{
struct menu_device *data = this_cpu_ptr(&menu_devices);
+ struct device *device = get_cpu_device(dev->cpu);
int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
int i;
unsigned int interactivity_req;
unsigned int expected_interval;
unsigned long nr_iowaiters, cpu_load;
+ int resume_latency = dev_pm_qos_read_value(device);
if (data->needs_update) {
menu_update(drv, dev);
data->needs_update = 0;
}
+ /* resume_latency is 0 means no restriction */
+ if (resume_latency && resume_latency < latency_req)
+ latency_req = resume_latency;
+
/* Special case when user has set very strict latency requirement */
if (unlikely(latency_req == 0))
return 0;