Commit 7d1a9417 authored by Thomas Gleixner's avatar Thomas Gleixner

x86: Use generic idle loop

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: default avatarSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130321215235.486594473@linutronix.deSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
parent aba92c9e
......@@ -97,6 +97,7 @@ config X86
select GENERIC_IOMAP
select DCACHE_WORD_ACCESS
select GENERIC_SMP_IDLE_THREAD
select GENERIC_IDLE_LOOP
select ARCH_WANT_IPC_PARSE_VERSION if X86_32
select HAVE_ARCH_SECCOMP_FILTER
select BUILDTIME_EXTABLE_SORT
......
......@@ -301,13 +301,7 @@ void exit_idle(void)
}
#endif
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* low exit latency (ie sit in a loop waiting for
* somebody to say that they'd like to reschedule)
*/
void cpu_idle(void)
void arch_cpu_idle_prepare(void)
{
/*
* If we're the non-boot CPU, nothing set the stack canary up
......@@ -317,71 +311,40 @@ void cpu_idle(void)
* canaries already on the stack wont ever trigger).
*/
boot_init_stack_canary();
current_thread_info()->status |= TS_POLLING;
while (1) {
tick_nohz_idle_enter();
while (!need_resched()) {
rmb();
if (cpu_is_offline(smp_processor_id()))
play_dead();
/*
* Idle routines should keep interrupts disabled
* from here on, until they go to idle.
* Otherwise, idle callbacks can misfire.
*/
local_touch_nmi();
local_irq_disable();
enter_idle();
/* Don't trace irqs off for idle */
stop_critical_timings();
/* enter_idle() needs rcu for notifiers */
rcu_idle_enter();
}
if (cpuidle_idle_call())
x86_idle();
void arch_cpu_idle_enter(void)
{
local_touch_nmi();
enter_idle();
}
rcu_idle_exit();
start_critical_timings();
void arch_cpu_idle_exit(void)
{
__exit_idle();
}
/* In many cases the interrupt that ended idle
has already called exit_idle. But some idle
loops can be woken up without interrupt. */
__exit_idle();
}
void arch_cpu_idle_dead(void)
{
play_dead();
}
tick_nohz_idle_exit();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
/*
* Called from the generic idle code.
*/
void arch_cpu_idle(void)
{
if (cpuidle_idle_call())
x86_idle();
}
/*
* We use this if we don't have any better
* idle routine..
* We use this if we don't have any better idle routine..
*/
void default_idle(void)
{
trace_cpu_idle_rcuidle(1, smp_processor_id());
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we
* test NEED_RESCHED:
*/
smp_mb();
if (!need_resched())
safe_halt(); /* enables interrupts racelessly */
else
local_irq_enable();
current_thread_info()->status |= TS_POLLING;
safe_halt();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
#ifdef CONFIG_APM_MODULE
......@@ -411,20 +374,6 @@ void stop_this_cpu(void *dummy)
halt();
}
/*
* On SMP it's slightly faster (but much more power-consuming!)
* to poll the ->work.need_resched flag instead of waiting for the
* cross-CPU IPI to arrive. Use this option with caution.
*/
static void poll_idle(void)
{
trace_cpu_idle_rcuidle(0, smp_processor_id());
local_irq_enable();
while (!need_resched())
cpu_relax();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
bool amd_e400_c1e_detected;
EXPORT_SYMBOL(amd_e400_c1e_detected);
......@@ -489,10 +438,10 @@ static void amd_e400_idle(void)
void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
{
#ifdef CONFIG_SMP
if (x86_idle == poll_idle && smp_num_siblings > 1)
if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1)
pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n");
#endif
if (x86_idle)
if (x86_idle || boot_option_idle_override == IDLE_POLL)
return;
if (cpu_has_amd_erratum(amd_erratum_400)) {
......@@ -517,8 +466,8 @@ static int __init idle_setup(char *str)
if (!strcmp(str, "poll")) {
pr_info("using polling idle threads\n");
x86_idle = poll_idle;
boot_option_idle_override = IDLE_POLL;
cpu_idle_poll_ctrl(true);
} else if (!strcmp(str, "halt")) {
/*
* When the boot option of idle=halt is added, halt is
......
......@@ -284,7 +284,7 @@ notrace static void __cpuinit start_secondary(void *unused)
x86_cpuinit.setup_percpu_clockev();
wmb();
cpu_idle();
cpu_startup_entry(CPUHP_ONLINE);
}
void __init smp_store_boot_cpu_info(void)
......
......@@ -95,7 +95,7 @@ static void __cpuinit cpu_bringup(void)
static void __cpuinit cpu_bringup_and_idle(void)
{
cpu_bringup();
cpu_idle();
cpu_startup_entry(CPUHP_ONLINE);
}
static int xen_smp_intr_init(unsigned int cpu)
......
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