[RFC PATCH V1 1/7] cpuidle: create bootparam "cpuidle.off=1"
From: Trinabh Gupta <hidden>
Date: 2011-06-07 16:29:34
Also in:
lkml
Subsystem:
cpu idle time management framework, documentation, the rest · Maintainers:
"Rafael J. Wysocki", Daniel Lezcano, Jonathan Corbet, Linus Torvalds
From: Len Brown <redacted> useful for disabling cpuidle to fall back to architecture-default idle loop cpuidle drivers and governors will fail to register. on x86 they'll say so: intel_idle: intel_idle yielding to (null) ACPI: acpi_idle yielding to (null) Signed-off-by: Len Brown <redacted> --- Documentation/kernel-parameters.txt | 3 +++ drivers/cpuidle/cpuidle.c | 10 ++++++++++ drivers/cpuidle/cpuidle.h | 1 + drivers/cpuidle/driver.c | 3 +++ drivers/cpuidle/governor.c | 3 +++ 5 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d9a203b..5697faf 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt@@ -546,6 +546,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. /proc/<pid>/coredump_filter. See also Documentation/filesystems/proc.txt. + cpuidle.off=1 [CPU_IDLE] + disable the cpuidle sub-system + cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 406be83..a171b9e 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c@@ -28,6 +28,12 @@ LIST_HEAD(cpuidle_detected_devices); static void (*pm_idle_old)(void); static int enabled_devices; +static int off __read_mostly; + +int cpuidle_disabled(void) +{ + return off; +} #if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT) static void cpuidle_kick_cpus(void)
@@ -397,6 +403,9 @@ static int __init cpuidle_init(void) { int ret; + if (cpuidle_disabled()) + return -ENODEV; + pm_idle_old = pm_idle; ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
@@ -408,4 +417,5 @@ static int __init cpuidle_init(void) return 0; } +module_param(off, int, 0444); core_initcall(cpuidle_init);
diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h
index 33e50d5..38c3fd8 100644
--- a/drivers/cpuidle/cpuidle.h
+++ b/drivers/cpuidle/cpuidle.h@@ -13,6 +13,7 @@ extern struct list_head cpuidle_governors; extern struct list_head cpuidle_detected_devices; extern struct mutex cpuidle_lock; extern spinlock_t cpuidle_driver_lock; +extern int cpuidle_disabled(void); /* idle loop */ extern void cpuidle_install_idle_handler(void);
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 33e3189..284d7af 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c@@ -50,6 +50,9 @@ int cpuidle_register_driver(struct cpuidle_driver *drv) if (!drv) return -EINVAL; + if (cpuidle_disabled()) + return -ENODEV; + spin_lock(&cpuidle_driver_lock); if (cpuidle_curr_driver) { spin_unlock(&cpuidle_driver_lock);
diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c
index 724c164..ea2f8e7 100644
--- a/drivers/cpuidle/governor.c
+++ b/drivers/cpuidle/governor.c@@ -81,6 +81,9 @@ int cpuidle_register_governor(struct cpuidle_governor *gov) if (!gov || !gov->select) return -EINVAL; + if (cpuidle_disabled()) + return -ENODEV; + mutex_lock(&cpuidle_lock); if (__cpuidle_find_governor(gov->name) == NULL) { ret = 0;