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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] timers: Track inactive timers and migrate them on cpu offline.
# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1275480791 -3600
# Node ID 5aabc6f94df5f275647d55caa24780eff0c81355
# Parent a3bdee5a20daf590ae7a440dad4e3b104b99c620
timers: Track inactive timers and migrate them on cpu offline.
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
xen/arch/x86/irq.c | 22 +++-----
xen/common/domain.c | 7 --
xen/common/schedule.c | 23 --------
xen/common/timer.c | 129 +++++++++++++++++++++++++++++++++---------------
xen/include/xen/timer.h | 85 +++++++++++--------------------
5 files changed, 131 insertions(+), 135 deletions(-)
diff -r a3bdee5a20da -r 5aabc6f94df5 xen/arch/x86/irq.c
--- a/xen/arch/x86/irq.c Wed Jun 02 10:54:32 2010 +0100
+++ b/xen/arch/x86/irq.c Wed Jun 02 13:13:11 2010 +0100
@@ -46,8 +46,6 @@ static DECLARE_BITMAP(used_vectors, NR_V
struct irq_cfg __read_mostly *irq_cfg = NULL;
-static struct timer *__read_mostly irq_guest_eoi_timer;
-
static DEFINE_SPINLOCK(vector_lock);
DEFINE_PER_CPU(vector_irq_t, vector_irq);
@@ -275,18 +273,15 @@ int init_irq_data(void)
irq_desc = xmalloc_array(struct irq_desc, nr_irqs);
irq_cfg = xmalloc_array(struct irq_cfg, nr_irqs);
irq_status = xmalloc_array(int, nr_irqs);
- irq_guest_eoi_timer = xmalloc_array(struct timer, nr_irqs);
irq_vector = xmalloc_array(u8, nr_irqs_gsi);
- if (!irq_desc || !irq_cfg || !irq_status ||! irq_vector ||
- !irq_guest_eoi_timer)
+ if ( !irq_desc || !irq_cfg || !irq_status ||! irq_vector )
return -ENOMEM;
memset(irq_desc, 0, nr_irqs * sizeof(*irq_desc));
memset(irq_cfg, 0, nr_irqs * sizeof(*irq_cfg));
memset(irq_status, 0, nr_irqs * sizeof(*irq_status));
memset(irq_vector, 0, nr_irqs_gsi * sizeof(*irq_vector));
- memset(irq_guest_eoi_timer, 0, nr_irqs * sizeof(*irq_guest_eoi_timer));
for (irq = 0; irq < nr_irqs; irq++) {
desc = irq_to_desc(irq);
@@ -741,6 +736,7 @@ typedef struct {
#define ACKTYPE_UNMASK 1 /* Unmask PIC hardware (from any CPU) */
#define ACKTYPE_EOI 2 /* EOI on the CPU that was interrupted */
cpumask_t cpu_eoi_map; /* CPUs that need to EOI this interrupt */
+ struct timer eoi_timer;
struct domain *guest[IRQ_MAX_GUESTS];
} irq_guest_action_t;
@@ -850,7 +846,7 @@ static void __do_IRQ_guest(int irq)
if ( already_pending == action->nr_guests )
{
- stop_timer(&irq_guest_eoi_timer[irq]);
+ stop_timer(&action->eoi_timer);
desc->handler->disable(irq);
desc->status |= IRQ_GUEST_EOI_PENDING;
for ( i = 0; i < already_pending; ++i )
@@ -866,9 +862,8 @@ static void __do_IRQ_guest(int irq)
* - skip the timer setup below.
*/
}
- init_timer(&irq_guest_eoi_timer[irq],
- irq_guest_eoi_timer_fn, desc, smp_processor_id());
- set_timer(&irq_guest_eoi_timer[irq], NOW() + MILLISECS(1));
+ migrate_timer(&action->eoi_timer, smp_processor_id());
+ set_timer(&action->eoi_timer, NOW() + MILLISECS(1));
}
}
@@ -979,7 +974,7 @@ static void __pirq_guest_eoi(struct doma
if ( action->ack_type == ACKTYPE_NONE )
{
ASSERT(!test_bit(pirq, d->pirq_mask));
- stop_timer(&irq_guest_eoi_timer[irq]);
+ stop_timer(&action->eoi_timer);
_irq_guest_eoi(desc);
}
@@ -1163,6 +1158,7 @@ int pirq_guest_bind(struct vcpu *v, int
action->shareable = will_share;
action->ack_type = pirq_acktype(v->domain, pirq);
cpus_clear(action->cpu_eoi_map);
+ init_timer(&action->eoi_timer, irq_guest_eoi_timer_fn, desc, 0);
desc->depth = 0;
desc->status |= IRQ_GUEST;
@@ -1267,7 +1263,7 @@ static irq_guest_action_t *__pirq_guest_
}
break;
case ACKTYPE_NONE:
- stop_timer(&irq_guest_eoi_timer[irq]);
+ stop_timer(&action->eoi_timer);
_irq_guest_eoi(desc);
break;
}
@@ -1309,7 +1305,7 @@ static irq_guest_action_t *__pirq_guest_
desc->action = NULL;
desc->status &= ~IRQ_GUEST;
desc->status &= ~IRQ_INPROGRESS;
- kill_timer(&irq_guest_eoi_timer[irq]);
+ kill_timer(&action->eoi_timer);
desc->handler->shutdown(irq);
/* Caller frees the old guest descriptor block. */
diff -r a3bdee5a20da -r 5aabc6f94df5 xen/common/domain.c
--- a/xen/common/domain.c Wed Jun 02 10:54:32 2010 +0100
+++ b/xen/common/domain.c Wed Jun 02 13:13:11 2010 +0100
@@ -847,12 +847,7 @@ long do_vcpu_op(int cmd, int vcpuid, XEN
(set.timeout_abs_ns < NOW()) )
return -ETIME;
- if ( v->singleshot_timer.cpu != smp_processor_id() )
- {
- stop_timer(&v->singleshot_timer);
- v->singleshot_timer.cpu = smp_processor_id();
- }
-
+ migrate_timer(&v->singleshot_timer, smp_processor_id());
set_timer(&v->singleshot_timer, set.timeout_abs_ns);
break;
diff -r a3bdee5a20da -r 5aabc6f94df5 xen/common/schedule.c
--- a/xen/common/schedule.c Wed Jun 02 10:54:32 2010 +0100
+++ b/xen/common/schedule.c Wed Jun 02 13:13:11 2010 +0100
@@ -475,18 +475,6 @@ int cpu_disable_scheduler(unsigned int c
cpus_setall(v->cpu_affinity);
}
- /*
- * Migrate single-shot timers to CPU0. A new cpu will automatically
- * be chosen when the timer is next re-set.
- */
- if ( v->singleshot_timer.cpu == cpu )
- {
- int cpu_mig = first_cpu(c->cpu_valid);
- if ( cpu_mig == cpu )
- cpu_mig = next_cpu(cpu_mig, c->cpu_valid);
- migrate_timer(&v->singleshot_timer, cpu_mig);
- }
-
if ( v->processor == cpu )
{
set_bit(_VPF_migrating, &v->pause_flags);
@@ -804,12 +792,7 @@ long do_set_timer_op(s_time_t timeout)
}
else
{
- if ( v->singleshot_timer.cpu != smp_processor_id() )
- {
- stop_timer(&v->singleshot_timer);
- v->singleshot_timer.cpu = smp_processor_id();
- }
-
+ migrate_timer(&v->singleshot_timer, smp_processor_id());
set_timer(&v->singleshot_timer, timeout);
}
@@ -890,8 +873,6 @@ static void vcpu_periodic_timer_work(str
s_time_t now = NOW();
uint64_t periodic_next_event;
- ASSERT(!active_timer(&v->periodic_timer));
-
if ( v->periodic_period == 0 )
return;
@@ -904,7 +885,7 @@ static void vcpu_periodic_timer_work(str
periodic_next_event = now + v->periodic_period;
}
- v->periodic_timer.cpu = smp_processor_id();
+ migrate_timer(&v->periodic_timer, smp_processor_id());
set_timer(&v->periodic_timer, periodic_next_event);
}
diff -r a3bdee5a20da -r 5aabc6f94df5 xen/common/timer.c
--- a/xen/common/timer.c Wed Jun 02 10:54:32 2010 +0100
+++ b/xen/common/timer.c Wed Jun 02 13:13:11 2010 +0100
@@ -35,6 +35,7 @@ struct timers {
struct timer **heap;
struct timer *list;
struct timer *running;
+ struct list_head inactive;
} __cacheline_aligned;
static DEFINE_PER_CPU(struct timers, timers);
@@ -169,8 +170,9 @@ static int add_to_list(struct timer **pp
* TIMER OPERATIONS.
*/
-static int remove_entry(struct timers *timers, struct timer *t)
-{
+static int remove_entry(struct timer *t)
+{
+ struct timers *timers = &per_cpu(timers, t->cpu);
int rc;
switch ( t->status )
@@ -186,15 +188,16 @@ static int remove_entry(struct timers *t
BUG();
}
- t->status = TIMER_STATUS_inactive;
+ t->status = TIMER_STATUS_invalid;
return rc;
}
-static int add_entry(struct timers *timers, struct timer *t)
-{
+static int add_entry(struct timer *t)
+{
+ struct timers *timers = &per_cpu(timers, t->cpu);
int rc;
- ASSERT(t->status == TIMER_STATUS_inactive);
+ ASSERT(t->status == TIMER_STATUS_invalid);
/* Try to add to heap. t->heap_offset indicates whether we succeed. */
t->heap_offset = 0;
@@ -209,18 +212,23 @@ static int add_entry(struct timers *time
return add_to_list(&timers->list, t);
}
-static inline void __add_timer(struct timer *timer)
-{
- int cpu = timer->cpu;
- if ( add_entry(&per_cpu(timers, cpu), timer) )
- cpu_raise_softirq(cpu, TIMER_SOFTIRQ);
-}
-
-static inline void __stop_timer(struct timer *timer)
-{
- int cpu = timer->cpu;
- if ( remove_entry(&per_cpu(timers, cpu), timer) )
- cpu_raise_softirq(cpu, TIMER_SOFTIRQ);
+static inline void activate_timer(struct timer *timer)
+{
+ ASSERT(timer->status == TIMER_STATUS_inactive);
+ timer->status = TIMER_STATUS_invalid;
+ list_del(&timer->inactive);
+
+ if ( add_entry(timer) )
+ cpu_raise_softirq(timer->cpu, TIMER_SOFTIRQ);
+}
+
+static inline void deactivate_timer(struct timer *timer)
+{
+ if ( remove_entry(timer) )
+ cpu_raise_softirq(timer->cpu, TIMER_SOFTIRQ);
+
+ timer->status = TIMER_STATUS_inactive;
+ list_add(&timer->inactive, &per_cpu(timers, timer->cpu).inactive);
}
static inline void timer_lock(struct timer *timer)
@@ -253,6 +261,32 @@ static inline void timer_unlock(struct t
do { timer_unlock(t); local_irq_restore(flags); } while ( 0 )
+static bool_t active_timer(struct timer *timer)
+{
+ ASSERT(timer->status >= TIMER_STATUS_inactive);
+ ASSERT(timer->status <= TIMER_STATUS_in_list);
+ return (timer->status >= TIMER_STATUS_in_heap);
+}
+
+
+void init_timer(
+ struct timer *timer,
+ void (*function)(void *),
+ void *data,
+ unsigned int cpu)
+{
+ unsigned long flags;
+ memset(timer, 0, sizeof(*timer));
+ timer->function = function;
+ timer->data = data;
+ timer->cpu = cpu;
+ timer->status = TIMER_STATUS_inactive;
+ timer_lock_irqsave(timer, flags);
+ list_add(&timer->inactive, &per_cpu(timers, cpu).inactive);
+ timer_unlock_irqrestore(timer, flags);
+}
+
+
void set_timer(struct timer *timer, s_time_t expires)
{
unsigned long flags;
@@ -260,13 +294,13 @@ void set_timer(struct timer *timer, s_ti
timer_lock_irqsave(timer, flags);
if ( active_timer(timer) )
- __stop_timer(timer);
+ deactivate_timer(timer);
timer->expires = expires;
timer->expires_end = expires + timer_slop;
if ( likely(timer->status != TIMER_STATUS_killed) )
- __add_timer(timer);
+ activate_timer(timer);
timer_unlock_irqrestore(timer, flags);
}
@@ -279,7 +313,7 @@ void stop_timer(struct timer *timer)
timer_lock_irqsave(timer, flags);
if ( active_timer(timer) )
- __stop_timer(timer);
+ deactivate_timer(timer);
timer_unlock_irqrestore(timer, flags);
}
@@ -287,7 +321,8 @@ void stop_timer(struct timer *timer)
void migrate_timer(struct timer *timer, unsigned int new_cpu)
{
- int old_cpu;
+ int old_cpu;
+ bool_t active;
unsigned long flags;
for ( ; ; )
@@ -313,16 +348,16 @@ void migrate_timer(struct timer *timer,
spin_unlock_irqrestore(&per_cpu(timers, new_cpu).lock, flags);
}
- if ( active_timer(timer) )
- {
- __stop_timer(timer);
- timer->cpu = new_cpu;
- __add_timer(timer);
- }
- else
- {
- timer->cpu = new_cpu;
- }
+ active = active_timer(timer);
+ if ( active )
+ deactivate_timer(timer);
+
+ list_del(&timer->inactive);
+ timer->cpu = new_cpu;
+ list_add(&timer->inactive, &per_cpu(timers, new_cpu).inactive);
+
+ if ( active )
+ activate_timer(timer);
spin_unlock(&per_cpu(timers, old_cpu).lock);
spin_unlock_irqrestore(&per_cpu(timers, new_cpu).lock, flags);
@@ -339,7 +374,9 @@ void kill_timer(struct timer *timer)
timer_lock_irqsave(timer, flags);
if ( active_timer(timer) )
- __stop_timer(timer);
+ deactivate_timer(timer);
+
+ list_del(&timer->inactive);
timer->status = TIMER_STATUS_killed;
timer_unlock_irqrestore(timer, flags);
@@ -354,6 +391,9 @@ static void execute_timer(struct timers
{
void (*fn)(void *) = t->function;
void *data = t->data;
+
+ t->status = TIMER_STATUS_inactive;
+ list_add(&t->inactive, &ts->inactive);
ts->running = t;
spin_unlock_irq(&ts->lock);
@@ -401,7 +441,6 @@ static void timer_softirq_action(void)
((t = heap[1])->expires < now) )
{
remove_from_heap(heap, t);
- t->status = TIMER_STATUS_inactive;
execute_timer(ts, t);
}
@@ -409,7 +448,6 @@ static void timer_softirq_action(void)
while ( ((t = ts->list) != NULL) && (t->expires < now) )
{
ts->list = t->list_next;
- t->status = TIMER_STATUS_inactive;
execute_timer(ts, t);
}
@@ -419,8 +457,8 @@ static void timer_softirq_action(void)
while ( unlikely((t = next) != NULL) )
{
next = t->list_next;
- t->status = TIMER_STATUS_inactive;
- add_entry(ts, t);
+ t->status = TIMER_STATUS_invalid;
+ add_entry(t);
}
ts->overflow = (ts->list != NULL);
@@ -446,7 +484,7 @@ static void timer_softirq_action(void)
while ( (GET_HEAP_SIZE(heap) != 0) &&
((t = heap[1])->expires <= end) )
{
- remove_entry(ts, t);
+ remove_entry(t);
t->status = TIMER_STATUS_in_list;
t->list_next = NULL;
@@ -529,13 +567,23 @@ static void migrate_timers_from_cpu(unsi
while ( (t = GET_HEAP_SIZE(ts->heap) ? ts->heap[1] : ts->list) != NULL )
{
- remove_entry(ts, t);
+ remove_entry(t);
t->cpu = 0;
- __add_timer(t);
+ add_entry(t);
+ }
+
+ while ( !list_empty(&ts->inactive) )
+ {
+ t = list_entry(ts->inactive.next, struct timer, inactive);
+ list_del(&t->inactive);
+ t->cpu = 0;
+ list_add(&t->inactive, &per_cpu(timers, 0).inactive);
}
spin_unlock(&ts->lock);
spin_unlock_irq(&per_cpu(timers, 0).lock);
+
+ cpu_raise_softirq(0, TIMER_SOFTIRQ);
}
static struct timer *dummy_heap;
@@ -549,6 +597,7 @@ static int cpu_callback(
switch ( action )
{
case CPU_UP_PREPARE:
+ INIT_LIST_HEAD(&ts->inactive);
spin_lock_init(&ts->lock);
ts->heap = &dummy_heap;
break;
diff -r a3bdee5a20da -r 5aabc6f94df5 xen/include/xen/timer.h
--- a/xen/include/xen/timer.h Wed Jun 02 10:54:32 2010 +0100
+++ b/xen/include/xen/timer.h Wed Jun 02 13:13:11 2010 +0100
@@ -11,6 +11,7 @@
#include <xen/spinlock.h>
#include <xen/time.h>
#include <xen/string.h>
+#include <xen/list.h>
struct timer {
/* System time expiry value (nanoseconds since boot). */
@@ -19,10 +20,12 @@ struct timer {
/* Position in active-timer data structure. */
union {
- /* Timer-heap offset. */
+ /* Timer-heap offset (TIMER_STATUS_in_heap). */
unsigned int heap_offset;
- /* Linked list. */
+ /* Linked list (TIMER_STATUS_in_list). */
struct timer *list_next;
+ /* Linked list of inactive timers (TIMER_STATUS_inactive). */
+ struct list_head inactive;
};
/* On expiry, '(*function)(data)' will be executed in softirq context. */
@@ -33,10 +36,11 @@ struct timer {
uint16_t cpu;
/* Timer status. */
-#define TIMER_STATUS_inactive 0 /* Not in use; can be activated. */
-#define TIMER_STATUS_killed 1 /* Not in use; canot be activated. */
-#define TIMER_STATUS_in_heap 2 /* In use; on timer heap. */
-#define TIMER_STATUS_in_list 3 /* In use; on overflow linked list. */
+#define TIMER_STATUS_invalid 0 /* Should never see this. */
+#define TIMER_STATUS_inactive 1 /* Not in use; can be activated. */
+#define TIMER_STATUS_killed 2 /* Not in use; cannot be activated. */
+#define TIMER_STATUS_in_heap 3 /* In use; on timer heap. */
+#define TIMER_STATUS_in_list 4 /* In use; on overflow linked list. */
uint8_t status;
};
@@ -45,67 +49,38 @@ struct timer {
*/
/*
- * Returns TRUE if the given timer is on a timer list.
- * The timer must *previously* have been initialised by init_timer(), or its
- * structure initialised to all-zeroes.
+ * Initialise a timer structure with an initial callback CPU, callback
+ * function and callback data pointer. This function must only be called on
+ * a brand new timer, or a killed timer. It must *never* execute concurrently
+ * with any other operation on the same timer.
*/
-static inline int active_timer(struct timer *timer)
-{
- return (timer->status >= TIMER_STATUS_in_heap);
-}
+void init_timer(
+ struct timer *timer,
+ void (*function)(void *),
+ void *data,
+ unsigned int cpu);
-/*
- * Initialise a timer structure with an initial callback CPU, callback
- * function and callback data pointer. This function may be called at any
- * time (and multiple times) on an inactive timer. It must *never* execute
- * concurrently with any other operation on the same timer.
- */
-static inline void init_timer(
- struct timer *timer,
- void (*function)(void *),
- void *data,
- unsigned int cpu)
-{
- memset(timer, 0, sizeof(*timer));
- timer->function = function;
- timer->data = data;
- timer->cpu = cpu;
-}
-
-/*
- * Set the expiry time and activate a timer. The timer must *previously* have
- * been initialised by init_timer() (so that callback details are known).
- */
-extern void set_timer(struct timer *timer, s_time_t expires);
+/* Set the expiry time and activate a timer. */
+void set_timer(struct timer *timer, s_time_t expires);
/*
* Deactivate a timer This function has no effect if the timer is not currently
* active.
- * The timer must *previously* have been initialised by init_timer(), or its
- * structure initialised to all zeroes.
*/
-extern void stop_timer(struct timer *timer);
+void stop_timer(struct timer *timer);
-/*
- * Migrate a timer to a different CPU. The timer may be currently active.
- * The timer must *previously* have been initialised by init_timer(), or its
- * structure initialised to all zeroes.
- */
-extern void migrate_timer(struct timer *timer, unsigned int new_cpu);
+/* Migrate a timer to a different CPU. The timer may be currently active. */
+void migrate_timer(struct timer *timer, unsigned int new_cpu);
/*
* Deactivate a timer and prevent it from being re-set (future calls to
* set_timer will silently fail). When this function returns it is guaranteed
* that the timer callback handler is not running on any CPU.
- * The timer must *previously* have been initialised by init_timer(), or its
- * structure initialised to all zeroes.
*/
-extern void kill_timer(struct timer *timer);
+void kill_timer(struct timer *timer);
-/*
- * Bootstrap initialisation. Must be called before any other timer function.
- */
-extern void timer_init(void);
+/* Bootstrap initialisation. Must be called before any other timer function. */
+void timer_init(void);
/*
* Next timer deadline for each CPU.
@@ -115,10 +90,10 @@ DECLARE_PER_CPU(s_time_t, timer_deadline
DECLARE_PER_CPU(s_time_t, timer_deadline_end);
/* Arch-defined function to reprogram timer hardware for new deadline. */
-extern int reprogram_timer(s_time_t timeout);
+int reprogram_timer(s_time_t timeout);
-/* calculate the aligned first tick time for a given periodic timer */
-extern s_time_t align_timer(s_time_t firsttick, uint64_t period);
+/* Calculate the aligned first tick time for a given periodic timer. */
+s_time_t align_timer(s_time_t firsttick, uint64_t period);
#endif /* _TIMER_H_ */
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