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tile: Use generic idle loop

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Signed-off-by: Thomas 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: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Link: http://lkml.kernel.org/r/20130321215235.348460344@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2013-03-21 22:50:01 +01:00
parent e26ef8fe72
commit 0dc8153cfe
3 changed files with 11 additions and 57 deletions
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1
arch/tile/Kconfig
View file

@ -22,6 +22,7 @@ config TILE
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select GENERIC_CLOCKEVENTS
select MODULES_USE_ELF_RELA
select GENERIC_IDLE_LOOP
# FIXME: investigate whether we need/want these options.
# select HAVE_IOREMAP_PROT

65
arch/tile/kernel/process.c
View file

@ -40,13 +40,11 @@
#include <arch/abi.h>
#include <arch/sim_def.h>
/*
* Use the (x86) "idle=poll" option to prefer low latency when leaving the
* idle loop over low power while in the idle loop, e.g. if we have
* one thread per core and we want to get threads out of futex waits fast.
*/
static int no_idle_nap;
static int __init idle_setup(char *str)
{
if (!str)
@ -54,64 +52,19 @@ static int __init idle_setup(char *str)
if (!strcmp(str, "poll")) {
pr_info("using polling idle threads.\n");
no_idle_nap = 1;
} else if (!strcmp(str, "halt"))
no_idle_nap = 0;
else
return -1;
return 0;
cpu_idle_poll_ctrl(true);
return 0;
} else if (!strcmp(str, "halt")) {
return 0;
}
return -1;
}
early_param("idle", idle_setup);
/*
* 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(void)
{
int cpu = smp_processor_id();
current_thread_info()->status |= TS_POLLING;
if (no_idle_nap) {
while (1) {
while (!need_resched())
cpu_relax();
schedule();
}
}
/* endless idle loop with no priority at all */
while (1) {
tick_nohz_idle_enter();
rcu_idle_enter();
while (!need_resched()) {
if (cpu_is_offline(cpu))
BUG(); /* no HOTPLUG_CPU */
local_irq_disable();
__get_cpu_var(irq_stat).idle_timestamp = jiffies;
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we
* test NEED_RESCHED:
*/
smp_mb();
if (!need_resched())
_cpu_idle();
else
local_irq_enable();
current_thread_info()->status |= TS_POLLING;
}
rcu_idle_exit();
tick_nohz_idle_exit();
schedule_preempt_disabled();
}
__get_cpu_var(irq_stat).idle_timestamp = jiffies;
_cpu_idle();
}
/*

2
arch/tile/kernel/smpboot.c
View file

@ -207,7 +207,7 @@ void __cpuinit online_secondary(void)
/* Set up tile-timer clock-event device on this cpu */
setup_tile_timer();
cpu_idle();
cpu_startup_entry(CPUHP_ONLINE);
}
int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)