Messages in this thread Patch in this message |  | | Date | Wed, 25 Mar 2015 16:13:09 -0400 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [PATCH 08/09] tick/xen: Provide and use tick_suspend_local() and tick_resume_local() |
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On Wed, Mar 25, 2015 at 01:11:04PM +0100, Rafael J. Wysocki wrote: > From: Thomas Gleixner <tglx@linutronix.de> > > Xen calls on every cpu into tick_resume() which is just wrong. > tick_resume() is for the syscore global suspend/resume invocation. > What XEN really wants is a per cpu local resume function. > > Provide a tick_resume_local() function and use it in XEN. > > Also provide a complementary tick_suspend_local() and modify > tick_unfreeze() and tick_freeze(), respectively, to use the > new local tick resume/suspend functions. > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> > Cc: David Vrabel <david.vrabel@citrix.com> > [ rjw: Combined two patches, rebased, modified subject/changelog ] > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > arch/x86/xen/suspend.c | 2 - > include/linux/tick.h | 6 ++-- > kernel/time/tick-broadcast.c | 24 ++++++++++++------ > kernel/time/tick-common.c | 57 +++++++++++++++++++++++++++++-------------- > kernel/time/tick-internal.h | 8 ++++-- > 5 files changed, 66 insertions(+), 31 deletions(-) > > Index: linux-pm/arch/x86/xen/suspend.c > =================================================================== > --- linux-pm.orig/arch/x86/xen/suspend.c > +++ linux-pm/arch/x86/xen/suspend.c > @@ -85,7 +85,7 @@ static void xen_vcpu_notify_restore(void > if (smp_processor_id() == 0) > return; > > - tick_resume(); > + tick_resume_local();
I am looking at Linus's tree and I see:
82 static void xen_vcpu_notify_restore(void *data) 83 { 84 unsigned long reason = (unsigned long)data; 85 86 /* Boot processor notified via generic timekeeping_resume() */ 87 if ( smp_processor_id() == 0) 88 return; 89 90 clockevents_notify(reason, NULL); 91 }
So there must be another patch that altered the clockevents_notify?
Is there an git tree with all of these patches?
> } > > void xen_arch_resume(void) > Index: linux-pm/include/linux/tick.h > =================================================================== > --- linux-pm.orig/include/linux/tick.h > +++ linux-pm/include/linux/tick.h > @@ -29,13 +29,13 @@ extern struct tick_device *tick_get_devi > extern void __init tick_init(void); > extern void tick_freeze(void); > extern void tick_unfreeze(void); > -/* Should be core only, but XEN resume magic abuses this interface */ > -extern void tick_resume(void); > +/* Should be core only, but XEN resume magic requires this */ > +extern void tick_resume_local(void); > #else /* CONFIG_GENERIC_CLOCKEVENTS */ > static inline void tick_init(void) { } > static inline void tick_freeze(void) { } > static inline void tick_unfreeze(void) { } > -static inline void tick_resume(void) { } > +static inline void tick_resume_local(void) { } > #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ > > #ifdef CONFIG_TICK_ONESHOT > Index: linux-pm/kernel/time/tick-broadcast.c > =================================================================== > --- linux-pm.orig/kernel/time/tick-broadcast.c > +++ linux-pm/kernel/time/tick-broadcast.c > @@ -455,11 +455,26 @@ void tick_suspend_broadcast(void) > raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); > } > > -int tick_resume_broadcast(void) > +/* > + * This is called from tick_resume_local() on a resuming CPU. That's > + * called from the core resume function, tick_unfreeze() and the magic XEN > + * resume hackery. > + * > + * In none of these cases the broadcast device mode can change and the > + * bit of the resuming CPU in the broadcast mask is safe as well. > + */ > +bool tick_resume_check_broadcast(void) > +{ > + if (tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT) > + return false; > + else > + return cpumask_test_cpu(smp_processor_id(), tick_broadcast_mask); > +} > + > +void tick_resume_broadcast(void) > { > struct clock_event_device *bc; > unsigned long flags; > - int broadcast = 0; > > raw_spin_lock_irqsave(&tick_broadcast_lock, flags); > > @@ -472,8 +487,6 @@ int tick_resume_broadcast(void) > case TICKDEV_MODE_PERIODIC: > if (!cpumask_empty(tick_broadcast_mask)) > tick_broadcast_start_periodic(bc); > - broadcast = cpumask_test_cpu(smp_processor_id(), > - tick_broadcast_mask); > break; > case TICKDEV_MODE_ONESHOT: > if (!cpumask_empty(tick_broadcast_mask)) > @@ -482,11 +495,8 @@ int tick_resume_broadcast(void) > } > } > raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); > - > - return broadcast; > } > > - > #ifdef CONFIG_TICK_ONESHOT > > static cpumask_var_t tick_broadcast_oneshot_mask; > Index: linux-pm/kernel/time/tick-common.c > =================================================================== > --- linux-pm.orig/kernel/time/tick-common.c > +++ linux-pm/kernel/time/tick-common.c > @@ -373,40 +373,32 @@ void tick_shutdown(unsigned int *cpup) > } > > /** > - * tick_suspend - Suspend the tick and the broadcast device > + * tick_suspend_local - Suspend the local tick device > * > - * Called from syscore_suspend() via timekeeping_suspend with only one > - * CPU online and interrupts disabled or from tick_unfreeze() under > - * tick_freeze_lock. > + * Called from the local cpu for freeze with interrupts disabled. > * > * No locks required. Nothing can change the per cpu device. > */ > -void tick_suspend(void) > +static void tick_suspend_local(void) > { > struct tick_device *td = this_cpu_ptr(&tick_cpu_device); > > clockevents_shutdown(td->evtdev); > - tick_suspend_broadcast(); > } > > /** > - * tick_resume - Resume the tick and the broadcast device > + * tick_resume_local - Resume the local tick device > * > - * Called from syscore_resume() via timekeeping_resume with only one > - * CPU online and interrupts disabled or from tick_unfreeze() under > - * tick_freeze_lock. > + * Called from the local CPU for unfreeze or XEN resume magic. > * > * No locks required. Nothing can change the per cpu device. > */ > -void tick_resume(void) > +void tick_resume_local(void) > { > - struct tick_device *td; > - int broadcast; > + struct tick_device *td = this_cpu_ptr(&tick_cpu_device); > + bool broadcast = tick_resume_check_broadcast(); > > - broadcast = tick_resume_broadcast(); > - td = this_cpu_ptr(&tick_cpu_device); > clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME); > - > if (!broadcast) { > if (td->mode == TICKDEV_MODE_PERIODIC) > tick_setup_periodic(td->evtdev, 0); > @@ -415,6 +407,35 @@ void tick_resume(void) > } > } > > +/** > + * tick_suspend - Suspend the tick and the broadcast device > + * > + * Called from syscore_suspend() via timekeeping_suspend with only one > + * CPU online and interrupts disabled or from tick_unfreeze() under > + * tick_freeze_lock. > + * > + * No locks required. Nothing can change the per cpu device. > + */ > +void tick_suspend(void) > +{ > + tick_suspend_local(); > + tick_suspend_broadcast(); > +} > + > +/** > + * tick_resume - Resume the tick and the broadcast device > + * > + * Called from syscore_resume() via timekeeping_resume with only one > + * CPU online and interrupts disabled. > + * > + * No locks required. Nothing can change the per cpu device. > + */ > +void tick_resume(void) > +{ > + tick_resume_broadcast(); > + tick_resume_local(); > +} > + > static DEFINE_RAW_SPINLOCK(tick_freeze_lock); > static unsigned int tick_freeze_depth; > > @@ -440,7 +461,7 @@ void tick_freeze(void) > timekeeping_suspend(); > timekeeping_suspend_count++; > } else { > - tick_suspend(); > + tick_suspend_local(); > } > > raw_spin_unlock(&tick_freeze_lock); > @@ -465,7 +486,7 @@ void tick_unfreeze(void) > smp_processor_id(), tick_freeze_depth, > timekeeping_suspend_count); > } else { > - tick_resume(); > + tick_resume_local(); > } > tick_freeze_depth--; > > Index: linux-pm/kernel/time/tick-internal.h > =================================================================== > --- linux-pm.orig/kernel/time/tick-internal.h > +++ linux-pm/kernel/time/tick-internal.h > @@ -23,6 +23,7 @@ extern void tick_check_new_device(struct > extern void tick_handover_do_timer(int *cpup); > extern void tick_shutdown(unsigned int *cpup); > extern void tick_suspend(void); > +extern void tick_resume(void); > extern bool tick_check_replacement(struct clock_event_device *curdev, > struct clock_event_device *newdev); > extern void tick_install_replacement(struct clock_event_device *dev); > @@ -42,6 +43,7 @@ extern int __clockevents_update_freq(str > extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt); > #else > static inline void tick_suspend(void) { } > +static inline void tick_resume(void) { } > #endif /* GENERIC_CLOCKEVENTS */ > > /* Oneshot related functions */ > @@ -80,7 +82,8 @@ extern int tick_is_broadcast_device(stru > extern void tick_broadcast_on_off(unsigned long reason, int *oncpu); > extern void tick_shutdown_broadcast(unsigned int *cpup); > extern void tick_suspend_broadcast(void); > -extern int tick_resume_broadcast(void); > +extern void tick_resume_broadcast(void); > +extern bool tick_resume_check_broadcast(void); > extern void tick_broadcast_init(void); > extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast); > extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq); > @@ -94,7 +97,8 @@ static inline void tick_do_periodic_broa > static inline void tick_broadcast_on_off(unsigned long reason, int *oncpu) { } > static inline void tick_shutdown_broadcast(unsigned int *cpup) { } > static inline void tick_suspend_broadcast(void) { } > -static inline int tick_resume_broadcast(void) { return 0; } > +static inline void tick_resume_broadcast(void) { } > +static inline bool tick_resume_check_broadcast(void) { return false; } > static inline void tick_broadcast_init(void) { } > static inline int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq) { return -ENODEV; } > >
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