- document describing CPU hotplug support in the Linux kernel.
cpu-load.txt
- document describing how CPU load statistics are collected.
+cpuidle/
+ - info on CPU_IDLE, CPU idle state management subsystem.
cpusets.txt
- documents the cpusets feature; assign CPUs and Mem to a set of tasks.
cputopology.txt
--- /dev/null
+
+ Supporting multiple CPU idle levels in kernel
+
+ cpuidle
+
+General Information:
+
+Various CPUs today support multiple idle levels that are differentiated
+by varying exit latencies and power consumption during idle.
+cpuidle is a generic in-kernel infrastructure that separates
+idle policy (governor) from idle mechanism (driver) and provides a
+standardized infrastructure to support independent development of
+governors and drivers.
+
+cpuidle resides under drivers/cpuidle.
+
+Boot options:
+"cpuidle_sysfs_switch"
+enables current_governor interface in /sys/devices/system/cpu/cpuidle/,
+which can be used to switch governors at run time. This boot option
+is meant for developer testing only. In normal usage, kernel picks the
+best governor based on governor ratings.
+SEE ALSO: sysfs.txt in this directory.
--- /dev/null
+
+
+ Supporting multiple CPU idle levels in kernel
+
+ cpuidle drivers
+
+
+
+
+cpuidle driver hooks into the cpuidle infrastructure and handles the
+architecture/platform dependent part of CPU idle states. Driver
+provides the platform idle state detection capability and also
+has mechanisms in place to support actual entry-exit into CPU idle states.
+
+cpuidle driver initializes the cpuidle_device structure for each CPU device
+and registers with cpuidle using cpuidle_register_device.
+
+It can also support the dynamic changes (like battery <-> AC), by using
+cpuidle_pause_and_lock, cpuidle_disable_device and cpuidle_enable_device,
+cpuidle_resume_and_unlock.
+
+Interfaces:
+extern int cpuidle_register_driver(struct cpuidle_driver *drv);
+extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
+extern int cpuidle_register_device(struct cpuidle_device *dev);
+extern void cpuidle_unregister_device(struct cpuidle_device *dev);
+
+extern void cpuidle_pause_and_lock(void);
+extern void cpuidle_resume_and_unlock(void);
+extern int cpuidle_enable_device(struct cpuidle_device *dev);
+extern void cpuidle_disable_device(struct cpuidle_device *dev);
--- /dev/null
+
+
+
+ Supporting multiple CPU idle levels in kernel
+
+ cpuidle governors
+
+
+
+
+cpuidle governor is policy routine that decides what idle state to enter at
+any given time. cpuidle core uses different callbacks to the governor.
+
+* enable() to enable governor for a particular device
+* disable() to disable governor for a particular device
+* select() to select an idle state to enter
+* reflect() called after returning from the idle state, which can be used
+ by the governor for some record keeping.
+
+More than one governor can be registered at the same time and
+users can switch between drivers using /sysfs interface (when enabled).
+More than one governor part is supported for developers to easily experiment
+with different governors. By default, most optimal governor based on your
+kernel configuration and platform will be selected by cpuidle.
+
+Interfaces:
+extern int cpuidle_register_governor(struct cpuidle_governor *gov);
+extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
+struct cpuidle_governor
--- /dev/null
+
+
+ Supporting multiple CPU idle levels in kernel
+
+ cpuidle sysfs
+
+System global cpuidle related information and tunables are under
+/sys/devices/system/cpu/cpuidle
+
+The current interfaces in this directory has self-explanatory names:
+* current_driver
+* current_governor_ro
+
+With cpuidle_sysfs_switch boot option (meant for developer testing)
+following objects are visible instead.
+* current_driver
+* available_governors
+* current_governor
+In this case users can switch the governor at run time by writing
+to current_governor.
+
+
+Per logical CPU specific cpuidle information are under
+/sys/devices/system/cpu/cpuX/cpuidle
+for each online cpu X
+
+--------------------------------------------------------------------------------
+# ls -lR /sys/devices/system/cpu/cpu0/cpuidle/
+/sys/devices/system/cpu/cpu0/cpuidle/:
+total 0
+drwxr-xr-x 2 root root 0 Feb 8 10:42 state0
+drwxr-xr-x 2 root root 0 Feb 8 10:42 state1
+drwxr-xr-x 2 root root 0 Feb 8 10:42 state2
+drwxr-xr-x 2 root root 0 Feb 8 10:42 state3
+
+/sys/devices/system/cpu/cpu0/cpuidle/state0:
+total 0
+-r--r--r-- 1 root root 4096 Feb 8 10:42 desc
+-r--r--r-- 1 root root 4096 Feb 8 10:42 latency
+-r--r--r-- 1 root root 4096 Feb 8 10:42 name
+-r--r--r-- 1 root root 4096 Feb 8 10:42 power
+-r--r--r-- 1 root root 4096 Feb 8 10:42 time
+-r--r--r-- 1 root root 4096 Feb 8 10:42 usage
+
+/sys/devices/system/cpu/cpu0/cpuidle/state1:
+total 0
+-r--r--r-- 1 root root 4096 Feb 8 10:42 desc
+-r--r--r-- 1 root root 4096 Feb 8 10:42 latency
+-r--r--r-- 1 root root 4096 Feb 8 10:42 name
+-r--r--r-- 1 root root 4096 Feb 8 10:42 power
+-r--r--r-- 1 root root 4096 Feb 8 10:42 time
+-r--r--r-- 1 root root 4096 Feb 8 10:42 usage
+
+/sys/devices/system/cpu/cpu0/cpuidle/state2:
+total 0
+-r--r--r-- 1 root root 4096 Feb 8 10:42 desc
+-r--r--r-- 1 root root 4096 Feb 8 10:42 latency
+-r--r--r-- 1 root root 4096 Feb 8 10:42 name
+-r--r--r-- 1 root root 4096 Feb 8 10:42 power
+-r--r--r-- 1 root root 4096 Feb 8 10:42 time
+-r--r--r-- 1 root root 4096 Feb 8 10:42 usage
+
+/sys/devices/system/cpu/cpu0/cpuidle/state3:
+total 0
+-r--r--r-- 1 root root 4096 Feb 8 10:42 desc
+-r--r--r-- 1 root root 4096 Feb 8 10:42 latency
+-r--r--r-- 1 root root 4096 Feb 8 10:42 name
+-r--r--r-- 1 root root 4096 Feb 8 10:42 power
+-r--r--r-- 1 root root 4096 Feb 8 10:42 time
+-r--r--r-- 1 root root 4096 Feb 8 10:42 usage
+--------------------------------------------------------------------------------
+
+
+* desc : Small description about the idle state (string)
+* latency : Latency to exit out of this idle state (in microseconds)
+* name : Name of the idle state (string)
+* power : Power consumed while in this idle state (in milliwatts)
+* time : Total time spent in this idle state (in microseconds)
+* usage : Number of times this state was entered (count)
printk(KERN_DEBUG "Monitor-Mwait will be used to enter C-%d "
"state\n", cx->type);
}
+ snprintf(cx->desc, ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x",
+ cx->address);
out:
set_cpus_allowed(current, saved_mask);
#endif /* CONFIG_ACPI_PROC_EVENT */
/* ACPI notifier chain */
-BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
+static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
{
return_ACPI_STATUS(status);
}
+ arg.integer.value = sleep_state;
status = acpi_evaluate_object(NULL, METHOD_NAME__WAK, &arg_list, NULL);
if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
ACPI_EXCEPTION((AE_INFO, status, "During Method _WAK"));
}
#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
-struct acpi_table_header *acpi_find_dsdt_initrd(void)
+static struct acpi_table_header *acpi_find_dsdt_initrd(void)
{
struct file *firmware_file;
mm_segment_t oldfs;
}
#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
-int __init acpi_no_initrd_override_setup(char *s)
+static int __init acpi_no_initrd_override_setup(char *s)
{
acpi_no_initrd_override = 1;
return 1;
* Otherwise, ignore this info and continue.
*/
cx.entry_method = ACPI_CSTATE_HALT;
+ snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
} else {
continue;
}
+ } else {
+ snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
+ cx.address);
}
+
obj = &(element->package.elements[2]);
if (obj->type != ACPI_TYPE_INTEGER)
continue;
return 0;
local_irq_disable();
+
+ /* Do not access any ACPI IO ports in suspend path */
+ if (acpi_idle_suspend) {
+ acpi_safe_halt();
+ local_irq_enable();
+ return 0;
+ }
+
if (pr->flags.bm_check)
acpi_idle_update_bm_rld(pr, cx);
return -EINVAL;
}
+ for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
+ dev->states[i].name[0] = '\0';
+ dev->states[i].desc[0] = '\0';
+ }
+
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
cx = &pr->power.states[i];
state = &dev->states[count];
cpuidle_set_statedata(state, cx);
snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
+ strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
state->exit_latency = cx->latency;
state->target_residency = cx->latency * latency_factor;
state->power_usage = cx->power;
cpuidle_set_statedata(state, NULL);
- snprintf(state->name, CPUIDLE_NAME_LEN, "C0 (poll idle)");
+ snprintf(state->name, CPUIDLE_NAME_LEN, "C0");
+ snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
state->exit_latency = 0;
state->target_residency = 0;
state->power_usage = -1;
return sprintf(buf, "%u\n", state->_name);\
}
-static ssize_t show_state_name(struct cpuidle_state *state, char *buf)
-{
- return sprintf(buf, "%s\n", state->name);
+#define define_show_state_str_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
+{ \
+ if (state->_name[0] == '\0')\
+ return sprintf(buf, "<null>\n");\
+ return sprintf(buf, "%s\n", state->_name);\
}
define_show_state_function(exit_latency)
define_show_state_function(power_usage)
define_show_state_function(usage)
define_show_state_function(time)
+define_show_state_str_function(name)
+define_show_state_str_function(desc)
+
define_one_state_ro(name, show_state_name);
+define_one_state_ro(desc, show_state_desc);
define_one_state_ro(latency, show_state_exit_latency);
define_one_state_ro(power, show_state_power_usage);
define_one_state_ro(usage, show_state_usage);
static struct attribute *cpuidle_state_default_attrs[] = {
&attr_name.attr,
+ &attr_desc.attr,
&attr_latency.attr,
&attr_power.attr,
&attr_usage.attr,
static struct device_attribute dev_attr_hotkey_wakeup_reason =
__ATTR(wakeup_reason, S_IRUGO, hotkey_wakeup_reason_show, NULL);
-void hotkey_wakeup_reason_notify_change(void)
+static void hotkey_wakeup_reason_notify_change(void)
{
if (tp_features.hotkey_mask)
sysfs_notify(&tpacpi_pdev->dev.kobj, NULL,
__ATTR(wakeup_hotunplug_complete, S_IRUGO,
hotkey_wakeup_hotunplug_complete_show, NULL);
-void hotkey_wakeup_hotunplug_complete_notify_change(void)
+static void hotkey_wakeup_hotunplug_complete_notify_change(void)
{
if (tp_features.hotkey_mask)
sysfs_notify(&tpacpi_pdev->dev.kobj, NULL,
* have irqs (PIC, Timer) because we call acpi_register_gsi.
* Finally, only devices that have a CRS method need to be in this list.
*/
-static struct __initdata acpi_device_id excluded_id_list[] = {
+static struct acpi_device_id excluded_id_list[] __initdata = {
{"PNP0C09", 0}, /* EC */
{"PNP0C0F", 0}, /* Link device */
{"PNP0000", 0}, /* PIC */
#define DOMAIN_COORD_TYPE_SW_ANY 0xfd
#define DOMAIN_COORD_TYPE_HW_ALL 0xfe
-#define ACPI_CSTATE_SYSTEMIO (0)
-#define ACPI_CSTATE_FFH (1)
-#define ACPI_CSTATE_HALT (2)
+#define ACPI_CSTATE_SYSTEMIO 0
+#define ACPI_CSTATE_FFH 1
+#define ACPI_CSTATE_HALT 2
+
+#define ACPI_CX_DESC_LEN 32
/* Power Management */
u64 time;
struct acpi_processor_cx_policy promotion;
struct acpi_processor_cx_policy demotion;
+ char desc[ACPI_CX_DESC_LEN];
};
struct acpi_processor_power {
#define CPUIDLE_STATE_MAX 8
#define CPUIDLE_NAME_LEN 16
+#define CPUIDLE_DESC_LEN 32
struct cpuidle_device;
struct cpuidle_state {
char name[CPUIDLE_NAME_LEN];
+ char desc[CPUIDLE_DESC_LEN];
void *driver_data;
unsigned int flags;
projects / linux-2.6-omap-h63xx.git / commitdiff