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yaml
---
r: 366144
b: refs/heads/master
c: 0dc8153
h: refs/heads/master
v: v3
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Thomas Gleixner committed Apr 8, 2013
1 parent 3b986dd commit d852831
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Showing 4 changed files with 12 additions and 58 deletions.
2 changes: 1 addition & 1 deletion [refs]
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@@ -1,2 +1,2 @@
---
refs/heads/master: e26ef8fe722d5c1c0c1a0212542da8fc2b21a89f
refs/heads/master: 0dc8153cfebac68c9523b8852b14f10b31209f08
1 change: 1 addition & 0 deletions trunk/arch/tile/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -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
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65 changes: 9 additions & 56 deletions trunk/arch/tile/kernel/process.c
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Expand Up @@ -40,78 +40,31 @@
#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)
return -EINVAL;

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();
}

/*
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2 changes: 1 addition & 1 deletion trunk/arch/tile/kernel/smpboot.c
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Expand Up @@ -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)
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