mirror of
https://github.com/torvalds/linux.git
synced 2024-11-24 21:21:41 +00:00
06f7c08751
gov has already been NULL checked at the beginning of cpuidle_switch_governor, so remove redundant check. While at it, use pr_info() instead printk() to address the following checkpatch warning: WARNING: Prefer [subsystem eg: netdev]_info([subsystem]dev, ... then dev_info(dev, ... then pr_info(... to printk(KERN_INFO ... Signed-off-by: Yu Liao <liaoyu15@huawei.com> [ rjw: Subject and changelog edits, added empty line after if () ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
120 lines
2.7 KiB
C
120 lines
2.7 KiB
C
/*
|
|
* governor.c - governor support
|
|
*
|
|
* (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
|
|
* Shaohua Li <shaohua.li@intel.com>
|
|
* Adam Belay <abelay@novell.com>
|
|
*
|
|
* This code is licenced under the GPL.
|
|
*/
|
|
|
|
#include <linux/cpu.h>
|
|
#include <linux/cpuidle.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/module.h>
|
|
#include <linux/pm_qos.h>
|
|
|
|
#include "cpuidle.h"
|
|
|
|
char param_governor[CPUIDLE_NAME_LEN];
|
|
|
|
LIST_HEAD(cpuidle_governors);
|
|
struct cpuidle_governor *cpuidle_curr_governor;
|
|
struct cpuidle_governor *cpuidle_prev_governor;
|
|
|
|
/**
|
|
* cpuidle_find_governor - finds a governor of the specified name
|
|
* @str: the name
|
|
*
|
|
* Must be called with cpuidle_lock acquired.
|
|
*/
|
|
struct cpuidle_governor *cpuidle_find_governor(const char *str)
|
|
{
|
|
struct cpuidle_governor *gov;
|
|
|
|
list_for_each_entry(gov, &cpuidle_governors, governor_list)
|
|
if (!strncasecmp(str, gov->name, CPUIDLE_NAME_LEN))
|
|
return gov;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* cpuidle_switch_governor - changes the governor
|
|
* @gov: the new target governor
|
|
* Must be called with cpuidle_lock acquired.
|
|
*/
|
|
int cpuidle_switch_governor(struct cpuidle_governor *gov)
|
|
{
|
|
struct cpuidle_device *dev;
|
|
|
|
if (!gov)
|
|
return -EINVAL;
|
|
|
|
if (gov == cpuidle_curr_governor)
|
|
return 0;
|
|
|
|
cpuidle_uninstall_idle_handler();
|
|
|
|
if (cpuidle_curr_governor) {
|
|
list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
|
|
cpuidle_disable_device(dev);
|
|
}
|
|
|
|
cpuidle_curr_governor = gov;
|
|
|
|
list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
|
|
cpuidle_enable_device(dev);
|
|
|
|
cpuidle_install_idle_handler();
|
|
pr_info("cpuidle: using governor %s\n", gov->name);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* cpuidle_register_governor - registers a governor
|
|
* @gov: the governor
|
|
*/
|
|
int cpuidle_register_governor(struct cpuidle_governor *gov)
|
|
{
|
|
int ret = -EEXIST;
|
|
|
|
if (!gov || !gov->select)
|
|
return -EINVAL;
|
|
|
|
if (cpuidle_disabled())
|
|
return -ENODEV;
|
|
|
|
mutex_lock(&cpuidle_lock);
|
|
if (cpuidle_find_governor(gov->name) == NULL) {
|
|
ret = 0;
|
|
list_add_tail(&gov->governor_list, &cpuidle_governors);
|
|
if (!cpuidle_curr_governor ||
|
|
!strncasecmp(param_governor, gov->name, CPUIDLE_NAME_LEN) ||
|
|
(cpuidle_curr_governor->rating < gov->rating &&
|
|
strncasecmp(param_governor, cpuidle_curr_governor->name,
|
|
CPUIDLE_NAME_LEN)))
|
|
cpuidle_switch_governor(gov);
|
|
}
|
|
mutex_unlock(&cpuidle_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* cpuidle_governor_latency_req - Compute a latency constraint for CPU
|
|
* @cpu: Target CPU
|
|
*/
|
|
s64 cpuidle_governor_latency_req(unsigned int cpu)
|
|
{
|
|
struct device *device = get_cpu_device(cpu);
|
|
int device_req = dev_pm_qos_raw_resume_latency(device);
|
|
int global_req = cpu_latency_qos_limit();
|
|
|
|
if (device_req > global_req)
|
|
device_req = global_req;
|
|
|
|
return (s64)device_req * NSEC_PER_USEC;
|
|
}
|