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add cpuidle-haltpoll driver

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Add a cpuidle driver that calls the architecture default_idle routine.

To be used in conjunction with the haltpoll governor.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Marcelo Tosatti 2019-07-03 20:51:25 -03:00 committed by Rafael J. Wysocki
parent 609488bc97
commit fa86ee90eb
4 changed files with 79 additions and 1 deletions
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2
arch/x86/kernel/process.c
View file

@ -580,7 +580,7 @@ void __cpuidle default_idle(void)
safe_halt();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
#ifdef CONFIG_APM_MODULE
#if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE)
EXPORT_SYMBOL(default_idle);
#endif

9
drivers/cpuidle/Kconfig
View file

@ -51,6 +51,15 @@ depends on PPC
source "drivers/cpuidle/Kconfig.powerpc"
endmenu
config HALTPOLL_CPUIDLE
tristate "Halt poll cpuidle driver"
depends on X86 && KVM_GUEST
default y
help
This option enables halt poll cpuidle driver, which allows to poll
before halting in the guest (more efficient than polling in the
host via halt_poll_ns for some scenarios).
endif
config ARCH_NEEDS_CPU_IDLE_COUPLED

1
drivers/cpuidle/Makefile
View file

@ -7,6 +7,7 @@ obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
obj-$(CONFIG_DT_IDLE_STATES) += dt_idle_states.o
obj-$(CONFIG_ARCH_HAS_CPU_RELAX) += poll_state.o
obj-$(CONFIG_HALTPOLL_CPUIDLE) += cpuidle-haltpoll.o
##################################################################################
# ARM SoC drivers

68
drivers/cpuidle/cpuidle-haltpoll.c Normal file
View file

@ -0,0 +1,68 @@
// SPDX-License-Identifier: GPL-2.0
/*
* cpuidle driver for haltpoll governor.
*
* Copyright 2019 Red Hat, Inc. and/or its affiliates.
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Authors: Marcelo Tosatti <mtosatti@redhat.com>
*/
#include <linux/init.h>
#include <linux/cpuidle.h>
#include <linux/module.h>
#include <linux/sched/idle.h>
#include <linux/kvm_para.h>
static int default_enter_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
if (current_clr_polling_and_test()) {
local_irq_enable();
return index;
}
default_idle();
return index;
}
static struct cpuidle_driver haltpoll_driver = {
.name = "haltpoll",
.owner = THIS_MODULE,
.states = {
{ /* entry 0 is for polling */ },
{
.enter = default_enter_idle,
.exit_latency = 1,
.target_residency = 1,
.power_usage = -1,
.name = "haltpoll idle",
.desc = "default architecture idle",
},
},
.safe_state_index = 0,
.state_count = 2,
};
static int __init haltpoll_init(void)
{
struct cpuidle_driver *drv = &haltpoll_driver;
cpuidle_poll_state_init(drv);
if (!kvm_para_available())
return 0;
return cpuidle_register(&haltpoll_driver, NULL);
}
static void __exit haltpoll_exit(void)
{
cpuidle_unregister(&haltpoll_driver);
}
module_init(haltpoll_init);
module_exit(haltpoll_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marcelo Tosatti <mtosatti@redhat.com>");