Mailing List Archive

# HG changeset patch
# User kaf24@firebug.cl.cam.ac.uk
# Node ID cc2f35c83b4cbc48e540ddb2e36571ed05917b93
# Parent d3279720963294702936ecb45d49cd4db8b5caaf
Add a new timer operation kill_timer(). Effectively the
'opposite' of init_timer(), it marks the end of a timer's
lifetime. After this call the timer will not be pending,
its callback handler will not be running, and future calls
to set_timer() will silently fail.

Signed-off-by: Keir Fraser <keir@xensource.com>

diff -r d32797209632 -r cc2f35c83b4c xen/arch/x86/vmx.c
--- a/xen/arch/x86/vmx.c Thu Jan 12 23:16:07 2006
+++ b/xen/arch/x86/vmx.c Fri Jan 13 00:03:44 2006
@@ -105,13 +105,11 @@
destroy_vmcs(&v->arch.arch_vmx);
free_monitor_pagetable(v);
vpit = &v->domain->arch.vmx_platform.vmx_pit;
- if ( active_timer(&(vpit->pit_timer)) )
- stop_timer(&vpit->pit_timer);
- if ( active_timer(&v->arch.arch_vmx.hlt_timer) )
- stop_timer(&v->arch.arch_vmx.hlt_timer);
+ kill_timer(&vpit->pit_timer);
+ kill_timer(&v->arch.arch_vmx.hlt_timer);
if ( vmx_apic_support(v->domain) && (VLAPIC(v) != NULL) )
{
- stop_timer(&VLAPIC(v)->vlapic_timer);
+ kill_timer(&VLAPIC(v)->vlapic_timer);
xfree(VLAPIC(v));
}
}
diff -r d32797209632 -r cc2f35c83b4c xen/common/sched_bvt.c
--- a/xen/common/sched_bvt.c Thu Jan 12 23:16:07 2006
+++ b/xen/common/sched_bvt.c Fri Jan 13 00:03:44 2006
@@ -45,9 +45,9 @@
limits*/
s32 warp_value; /* virtual time warp */
s_time_t warpl; /* warp limit */
- struct timer warp_timer; /* deals with warpl */
+ struct timer warp_timer; /* deals with warpl */
s_time_t warpu; /* unwarp time requirement */
- struct timer unwarp_timer; /* deals with warpu */
+ struct timer unwarp_timer; /* deals with warpu */

struct bvt_vcpu_info vcpu_inf[MAX_VIRT_CPUS];
};
@@ -168,6 +168,7 @@
static int bvt_alloc_task(struct vcpu *v)
{
struct domain *d = v->domain;
+ struct bvt_dom_info *inf;

if ( (d->sched_priv == NULL) )
{
@@ -176,32 +177,12 @@
memset(d->sched_priv, 0, sizeof(struct bvt_dom_info));
}

- v->sched_priv = &BVT_INFO(d)->vcpu_inf[v->vcpu_id];
-
- BVT_INFO(d)->vcpu_inf[v->vcpu_id].inf = BVT_INFO(d);
- BVT_INFO(d)->vcpu_inf[v->vcpu_id].vcpu = v;
-
- return 0;
-}
-
-/*
- * Add and remove a domain
- */
-static void bvt_add_task(struct vcpu *v)
-{
- struct bvt_dom_info *inf = BVT_INFO(v->domain);
- struct bvt_vcpu_info *einf = EBVT_INFO(v);
- ASSERT(inf != NULL);
- ASSERT(v != NULL);
-
- /* Allocate per-CPU context if this is the first domain to be added. */
- if ( CPU_INFO(v->processor) == NULL )
- {
- schedule_data[v->processor].sched_priv = xmalloc(struct bvt_cpu_info);
- BUG_ON(CPU_INFO(v->processor) == NULL);
- INIT_LIST_HEAD(RUNQUEUE(v->processor));
- CPU_SVT(v->processor) = 0;
- }
+ inf = BVT_INFO(d);
+
+ v->sched_priv = &inf->vcpu_inf[v->vcpu_id];
+
+ inf->vcpu_inf[v->vcpu_id].inf = BVT_INFO(d);
+ inf->vcpu_inf[v->vcpu_id].vcpu = v;

if ( v->vcpu_id == 0 )
{
@@ -218,7 +199,28 @@
init_timer(&inf->unwarp_timer, unwarp_timer_fn, inf, v->processor);
}

- einf->vcpu = v;
+ return 0;
+}
+
+/*
+ * Add and remove a domain
+ */
+static void bvt_add_task(struct vcpu *v)
+{
+ struct bvt_dom_info *inf = BVT_INFO(v->domain);
+ struct bvt_vcpu_info *einf = EBVT_INFO(v);
+
+ ASSERT(inf != NULL);
+ ASSERT(v != NULL);
+
+ /* Allocate per-CPU context if this is the first domain to be added. */
+ if ( CPU_INFO(v->processor) == NULL )
+ {
+ schedule_data[v->processor].sched_priv = xmalloc(struct bvt_cpu_info);
+ BUG_ON(CPU_INFO(v->processor) == NULL);
+ INIT_LIST_HEAD(RUNQUEUE(v->processor));
+ CPU_SVT(v->processor) = 0;
+ }

if ( is_idle_vcpu(v) )
{
@@ -305,8 +307,14 @@
*/
static void bvt_free_task(struct domain *d)
{
- ASSERT(d->sched_priv != NULL);
- xfree(d->sched_priv);
+ struct bvt_dom_info *inf = BVT_INFO(d);
+
+ ASSERT(inf != NULL);
+
+ kill_timer(&inf->warp_timer);
+ kill_timer(&inf->unwarp_timer);
+
+ xfree(inf);
}

/* Control the scheduler. */
diff -r d32797209632 -r cc2f35c83b4c xen/common/schedule.c
--- a/xen/common/schedule.c Thu Jan 12 23:16:07 2006
+++ b/xen/common/schedule.c Fri Jan 13 00:03:44 2006
@@ -156,7 +156,7 @@

void sched_rem_domain(struct vcpu *v)
{
- stop_timer(&v->timer);
+ kill_timer(&v->timer);
SCHED_OP(rem_task, v);
TRACE_2D(TRC_SCHED_DOM_REM, v->domain->domain_id, v->vcpu_id);
}
@@ -462,7 +462,7 @@
/* Periodic tick timer: send timer event to current domain */
static void t_timer_fn(void *unused)
{
- struct vcpu *v = current;
+ struct vcpu *v = current;
unsigned int cpu = smp_processor_id();

schedule_data[cpu].tick++;
diff -r d32797209632 -r cc2f35c83b4c xen/common/timer.c
--- a/xen/common/timer.c Thu Jan 12 23:16:07 2006
+++ b/xen/common/timer.c Fri Jan 13 00:03:44 2006
@@ -29,6 +29,7 @@
struct timers {
spinlock_t lock;
struct timer **heap;
+ struct timer *running;
} __cacheline_aligned;

struct timers timers[NR_CPUS];
@@ -167,11 +168,11 @@
unsigned long flags;

spin_lock_irqsave(&timers[cpu].lock, flags);
- ASSERT(timer != NULL);
if ( active_timer(timer) )
__stop_timer(timer);
timer->expires = expires;
- __add_timer(timer);
+ if ( likely(!timer->killed) )
+ __add_timer(timer);
spin_unlock_irqrestore(&timers[cpu].lock, flags);
}

@@ -182,10 +183,28 @@
unsigned long flags;

spin_lock_irqsave(&timers[cpu].lock, flags);
- ASSERT(timer != NULL);
if ( active_timer(timer) )
__stop_timer(timer);
spin_unlock_irqrestore(&timers[cpu].lock, flags);
+}
+
+
+void kill_timer(struct timer *timer)
+{
+ int cpu = timer->cpu;
+ unsigned long flags;
+
+ BUG_ON(timers[cpu].running == timer);
+
+ spin_lock_irqsave(&timers[cpu].lock, flags);
+ if ( active_timer(timer) )
+ __stop_timer(timer);
+ timer->killed = 1;
+ spin_unlock_irqrestore(&timers[cpu].lock, flags);
+
+ for_each_online_cpu ( cpu )
+ while ( timers[cpu].running == timer )
+ cpu_relax();
}


@@ -208,19 +227,20 @@
{
remove_entry(heap, t);

+ timers[cpu].running = t;
+
fn = t->function;
data = t->data;

- if ( fn != NULL )
- {
- spin_unlock_irq(&timers[cpu].lock);
- (*fn)(data);
- spin_lock_irq(&timers[cpu].lock);
- }
+ spin_unlock_irq(&timers[cpu].lock);
+ (*fn)(data);
+ spin_lock_irq(&timers[cpu].lock);

/* Heap may have grown while the lock was released. */
heap = timers[cpu].heap;
}
+
+ timers[cpu].running = NULL;
}
while ( !reprogram_timer(GET_HEAP_SIZE(heap) ? heap[1]->expires : 0) );

diff -r d32797209632 -r cc2f35c83b4c xen/include/xen/timer.h
--- a/xen/include/xen/timer.h Thu Jan 12 23:16:07 2006
+++ b/xen/include/xen/timer.h Fri Jan 13 00:03:44 2006
@@ -22,6 +22,8 @@
void *data;
/* Timer-heap offset. */
unsigned int heap_offset;
+ /* Has this timer been killed (cannot be activated)? */
+ int killed;
};

/*
@@ -64,6 +66,13 @@
extern void stop_timer(struct timer *timer);

/*
+ * 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.
+ */
+extern void kill_timer(struct timer *timer);
+
+/*
* Initialisation. Must be called before any other timer function.
*/
extern void timer_init(void);

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