On 03/22/2013 03:23 AM, Thomas Gleixner wrote: > Signed-off-by: Thomas Gleixner <[email protected]> > Cc: Benjamin Herrenschmidt <[email protected]> > --- [...] > Index: linux-2.6/arch/powerpc/kernel/idle.c > =================================================================== > --- linux-2.6.orig/arch/powerpc/kernel/idle.c > +++ linux-2.6/arch/powerpc/kernel/idle.c > @@ -50,64 +50,30 @@ static int __init powersave_off(char *ar > } > __setup("powersave=off", powersave_off); > > -/* > - * The body of the idle task. > - */ > -void cpu_idle(void) > +void arch_cpu_idle(void) > { > - set_thread_flag(TIF_POLLING_NRFLAG); > - while (1) { > - tick_nohz_idle_enter(); > - rcu_idle_enter(); > - > - while (!need_resched() && !cpu_should_die()) { > - ppc64_runlatch_off(); > - > - if (ppc_md.power_save) { > - clear_thread_flag(TIF_POLLING_NRFLAG); > - /* > - * smp_mb is so clearing of TIF_POLLING_NRFLAG > - * is ordered w.r.t. need_resched() test. > - */ > - smp_mb(); > - local_irq_disable(); > - > - /* Don't trace irqs off for idle */ > - stop_critical_timings(); > - > - /* check again after disabling irqs */ > - if (!need_resched() && !cpu_should_die()) > - ppc_md.power_save(); > - > - start_critical_timings(); > - > - /* Some power_save functions return with > - * interrupts enabled, some don't. > - */ > - if (irqs_disabled()) > - local_irq_enable(); > - set_thread_flag(TIF_POLLING_NRFLAG); > - > - } else { > - /* > - * Go into low thread priority and possibly > - * low power mode. > - */ > - HMT_low(); > - HMT_very_low(); > - } > - } > - > - HMT_medium(); > - ppc64_runlatch_on(); > - rcu_idle_exit(); > - tick_nohz_idle_exit(); > - if (cpu_should_die()) { > - sched_preempt_enable_no_resched(); > - cpu_die(); > - } > - schedule_preempt_disabled(); > + ppc64_runlatch_off(); > + > + if (ppc_md.power_save) { > + ppc_md.power_save(); > + /* > + * Some power_save functions return with > + * interrupts enabled, some don't. > + */ > + if (irqs_disabled()) > + local_irq_enable(); > + } else { > + local_irq_enable(); > + /* > + * Go into low thread priority and possibly > + * low power mode. > + */ > + HMT_low(); > + HMT_very_low(); > } > + > + HMT_medium(); > + ppc64_runlatch_on(); > } >
The call to cpu_die() seems to be missing. And considering this commit, commit a7c2bb8279d20d853e43c34584eaf2b039de8026 Author: Signed-off-by: Darren Hart <[email protected]> Date: Wed Aug 4 18:28:33 2010 +0000 powerpc: Re-enable preemption before cpu_die() we need to call it with preempt enabled. So how about folding the following diff with this patch? diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c index b751baa..e434fb9 100644 --- a/arch/powerpc/kernel/idle.c +++ b/arch/powerpc/kernel/idle.c @@ -33,11 +33,6 @@ #include <asm/runlatch.h> #include <asm/smp.h> -#ifdef CONFIG_HOTPLUG_CPU -#define cpu_should_die() cpu_is_offline(smp_processor_id()) -#else -#define cpu_should_die() 0 -#endif unsigned long cpuidle_disable = IDLE_NO_OVERRIDE; EXPORT_SYMBOL(cpuidle_disable); @@ -50,6 +45,12 @@ static int __init powersave_off(char *arg) } __setup("powersave=off", powersave_off); +void arch_cpu_idle_dead(void) +{ + sched_preempt_enable_no_resched(); + cpu_die(); +} + void arch_cpu_idle(void) { ppc64_runlatch_off(); Regards, Srivatsa S. Bhat -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
